lesson guide - gr. 3 chapter iv -measurement -area v1.0.pdf

7/24/2019 LESSON GUIDE - Gr. 3 Chapter IV -Measurement -Area v1.0.pdf

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Lesson Guide

In

Elementary MathematicsGrade 3

Reformatted for distribution via

DepEd LEARNING RESOURCE MANAGEMENT and DEVELOPMENT SYSTEM PORTAL

DEPARTMENT OF EDUCATIONBUREAU OF ELEMENTARY EDUCATION

in coordination with

ATENEO DE MANILA UNIVERSITY

2010

Chapter IV

Measurement

Area

INSTRUCTIONAL MATERIALSCOUNCIL SECRETARIAT, 2011


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Lesson Guides in Elementary Mathematics

Grade III

Copyright 2003All rights reserved. No part of these lesson guides shall be reproduced in any form without a writtenpermission from the Bureau of Elementary Education, Department of Education.

The Mathematics Writing Committee

GRADE 3

Region 3

Agnes V. CanilaoPampangaJosefina S. AboTarlac CityAlma FloresBataan

Region 4 - A

Cesar MojicaRegional OfficeMarissa J. de AldayQuezonHenry P. ContemplacionSan Pablo City

Region 4 BFelicima MurciaPalawan

National Capital Region (NCR)

Laura N. GonzagaQuezon CityDionicia PaguiriganPasig/San JuanYolita SangalangPasig/San Juan

Bureau of Elementary Education (BEE)

Elizabeth J. EscaoGalileo L. GoNerisa M. Beltran

Ateneo de Manila University

Pacita E. Hosaka

Support Staff

Ferdinand S. BergadoMa. Cristina C. Capellan

Emilene Judith S. SisonJulius Peter M. SamuldeRoy L. ConcepcionMarcelino C. BatallerMyrna D. LatozaEric S. de Guia - Illustrator

Consultants

Fr. Bienvenido F. Nebres, SJPresident,Ateneo de Manila University

Ms. Carmela C. OracionPrincipal,Ateneo de Manila UniversityHigh School

Ms. Pacita E. HosakaAteneo de ManilaUniversity

Project Management

Yolanda S. QuijanoDirector IVAngelita M. EsdiculDirector III

Simeona T. EbolChief, Curriculum Development DivisionIrene C. RoblesOIC - Asst. Chief, Curriculum Development Division

Virginia T. FernandezProject Coordinator

EXECUTIVE COMMITTEE

Jesli A. LapusSecretary, Department of EducationTeodosio C. Sangil, Jr.Undersecretary for Finance and Administration

Jesus G. GalvanOIC - Undersecretary for Programs and ProjectsTeresita G. InciongAssistant Secretary for Programs and Projects

Printed By:

ISBN

971-92775-2-1


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TABLE OF CONTENTS

Introduction .................................................................................................................................. ivMatrix ........................................................................................................................................ v

IV. MEASUREMENTS

A. Area

Visualizing Area of Rectangle ......................................................................................... 1Visualizing Area of Square .............................................................................................. 5Deriving a Formula for Finding

Area of Rectangle .............................................................................................. 9

Area of Square ................................................................................................... 13

Solving Word Problem Involving

Area of Rectangle. ............................................................................................. 19

Area of Square ................................................................................................... 22


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I N T R O D U C T I O N

The Lesson Guides in Elementary Mathematics were developed by the

Department of Education through the Bureau of Elementary Education in

coordination with the Ateneo de Manila University. These resource materials

have been purposely prepared to help improve the mathematics instruction in

the elementary grades. These provide integration of values and life skills using

different teaching strategies for an interactive teaching/learning process.

Multiple intelligences techniques like games, puzzles, songs, etc. are also

integrated in each lesson; hence, learning Mathematics becomes fun and

enjoyable. Furthermore, Higher Order Thinking Skills (HOTS) activities are

incorporated in the lessons.

The skills are consistent with the Basic Education Curriculum

(BEC)/Philippine Elementary Learning Competencies (PELC). These should be

used by the teachers as a guide in their day-to-day teaching plans.


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MATRIX IN ELEMENTARY MATHEMATICSGrade III

COMPETENCIES VALUES INTEGRATED STRATEGIES USEDMULTIPLE INTELLIGENCES

TECHNIQUESWith HOTS

IV. Measurement

A. Comprehension of Area

1. Find the area of a figure in squaremeters

1.1 Visualize the area of a rectangle Sportsmanship Modeling "Paper Folding" Singing (Musical) Manipulative(Bodily kinesthetic)

1.2 Visualize the area of a square Cooperation ModelingDrawing pictures

Play (Bodily kinesthetic)Puzzle (Logical mathematics)

1.3 Derive a formula for finding thearea of a rectangle/square

1.3.1 Derive a formula for findingthe area of a rectangle

Self-discipline Simplifying the problem Cooperativegroups(Interpersonal)

1.3.2 Derive a formula for findingthe area of a square

Teamwork Drawing picturesModeling

Drawing (Spatial)Play, Movement (Bodilykinesthetic)

2. Application of concept of area

2.1 Solve word problems involvingarea of

2.1.1 rectangle Industry Polya's steps in problemsolving

Puzzle (Logical mathematics)Outdoor activity (Naturalist)

2.1.2 square Thriftiness Modeling Simplifying theproblem

Movements (BodilyKinesthetic)


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Visualizing Area of Rectangle

I. Learning Objectives

Cognitive: Visualize the area of rectanglesPsychomotor: Show the area of rectangles

Affective: Participate in class activity

II. Learning Content

Skill: Visualizing the area of rectanglesShowing the area of rectangles

Reference: BEC PELC III C-1.1Materials: textbooks and teachers manual in Math III, rectangular shape/cut-outs of figures,

cartolina, illustration board, pentel pen, chart, manila paperValue: Sportsmanship/cooperation

III. Learning Experiences

A. Preparatory Activities

1. Drill/Review

a. How many sides are there in a square?What can you say about its sides?

b. How many square units are there in the figure?

2. Motivation

Lets sing a song(Tune: Bahay-Kubo)Whats Mang Kiko made ofWhats Mang Kiko made of (3)

and

andThats what Mang Kiko is made ofWhat is Mang Kiko made of?

B. Developmental Activities

1. Presentationa. Present square cut-outs to the pupils.

Ask: What do you call this figure?How many squares do you think would cover the surface of the chalkboard?

b. Ask some pupils to cover the chalkboard with square cut-outs and count the number ofsquares.

c. Ask: How many square units did you use to cover the chalkboard.d. Ask: How many square units are there in its rows? Column?e. Ask: Which is longer, square units in rows or in columns?f. Introducethe length and width of the rectangle.


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g. Ask: Which has more square units, the length or the width?h. Show cut out of this figure.

i. Ask: How many square units are there in this figure?j. Ask: How many square units are there in the length this figure? width?

2. Using Geoboard the teacher shows different number of squares using rubber bands.

- Let the pupils count the number of squares on the geo-board.

Example:

3. Guided Practice

a. Paper folding Group the class into five groups. Each group must have pieces ofrectangular sheets.

1. Fold the paper into many square units as you can.2. Guide the pupils in doing the activity.3. Ask: How many square units did you form?4. Ask: How many square units are there in the length of this paper? width?5. Ask: Which is longer? the length or the width?

b. Oral exercises1. The teacher presents rectangles with different square units written on

cartolina/manila paper.


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1.

2. Ask: How many square units are there in figure 1?

How many square units are there in its length? width?

2. 3. 4.

3. Give more examples.

4. Paper Dot

- Group in pairsa. Distribute the paper dots to the pupilsb. Connect the dots and form rectangles. Count the square units.c. How many square units are in its length? width?d. Make a rectangle with an area of a. 20 b. 36 c. 24 d. 32 e. 28.

3. Generalization

How will you know the number of square units of a figure?

By counting the number of square units inside the figure.

C. Application

A. Draw the figure being described.

1. A rectangular board5 square units long and 2 square units wide.


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2. A table that measures 3 square units wide and 4 square units long.3. Draw the square units of a rectangular tiled floor with 18 square units.4. A bed that measures 5 square units and 3 square units.5. A blackboard which is 6 square units and 5 square units.

Work in groups of four.

B. Find the area of each shaded figure by counting the number of square units.

C D

A B

E

F

A = ____ square units D = _____ square units

B = ____ square units E = _____ square units

C = ____ square units F = _____ square units

IV. Evaluation

Answer the following in your notebook.

1. How many square units are in the figure?

_____ square units

2. What is the area of the rectangle?

_____ square units

3. Father has a garden. Its area is 10 square units. Draw the square units.

5

2


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4.5. Draw the rectangular area using the given square units.

a. 12 square unitsb. 20 square units

V. Assignment

Draw rectangles with the following square units.1. 15 square units2. 48 square units3. 12 square units4. 21 square units5. 28 square units

Visualizing the Area of Square


Cognitive: Visualize the area of squarePsychomotor: Show the area of squareAffective: Cooperate actively


Skill: Visualizing the area of squareShowing the area of square

Reference: BEC PELC IVB 1.2Materials: textbooks and teachers manual in Math III, square things/cut -outs of figures,

cartolina, illustration board, pentel pen, chart, manila paper, rulerValue: Cooperation



1. Drill/Review

Let us play. Group yourselves into 10.I have here 5 boxes. Each box has different shapes.Group the things the way you want.

How did you group the different shapes? Group I? Group II? III? IV? (Pupils will defendtheir answer.)

2. Motivation

Answer the questions about the puzzle.

a. How many different-sized squares are there?

b. How many squares are there like ?


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c. How many squares are there like ?(Hint: There are more than 4)

d. How many squares are there like ?(Hint: There are more than 1)

e. How many total squares are there in all sizes?


1. Presentation

a. Present square cut-outs to the pupils.

Ask: What do you call this figure?How many squares of this size, do you think would be enough to cover

the surface of the teachers table?b. Ask some pupils to cover the table with square cut-outs and count the number of

squares.c. Introduce the term square units.

Ask: How many square units did you use to cover the table?d. Show other cut-outs of figures as shown on the cartolina/manila paper.

A B

Ask: How many square units are there in figure A? B?In figure A, how many square units are there in the rows?In the columns? (3 rows, 3 columns = 3 x 3)

e. Introduce the term Area.f. Lead them to come up with rows and columns and finally a multiplication sentence.

Figure B. (4 rows, 4 columns = 4 x 4)g. Give more examples.

2. Guided Practice:

a. Cooperative Learning: Stress the value of cooperation.1) Giant Steps

Pupils will be grouped into twoTeam A and Team B.Each correct answer is one step.

Sample Questions:1. How many square units are there in this figure?2. How many square units are there in its rows? Columns?


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3. Give the total number of squares.

2) Paper dot (Pair Square)

1. Distribute paper dots to groups.2. Connect dots and form a square. Count the square units.3. Make a square with an area of a. 25 b. 36 c. 64 d. 81 e. 150. Compare

their side and area.

3. Generalization

How will you know the number of square units of the figure?

By counting the number of square units inside the figure.

C. Application

Work in pairsShow figures on the board.

IV. Evaluation

A. What is the total number of square units in the following squares?

1.

_____ square units

2.

_____ square units

Questions to be answered:1. How many square units are there in

figure at the left?

2. How many square units are in itsrows? Columns?

3. Give the total number of squares.


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3.

_____ square units

4.

_____ square units

5.

_____ square units

B. Read and analyze each problem, Draw what is asked.

1. If the side of the square is 7 units what is the area?2. The side of the handkerchief is 8 units. What is the area?3. Give the area of a square room whose one side measures 10 units?4. Mrs. Estrella has a square flower garden with one side measuring 9 units. What is the area of

the garden?5. What is the area of a square table, with one side measuring 2 units?

V. Assignment

Draw a square with the following square units.

1. 4 square units2. 8 square units3. 16 square units4. 9 square units5. 12 square units


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Deriving a Formula for Finding the Area of Rectangle


Cognitive: Derive a formula for finding the area of rectangle

Psychomotor: Tell a formula for finding the area of rectangleUse the formula in finding the area of a rectangle

Affective: Observe self-discipline


Skills: Deriving a formula for finding the area of rectangleTelling a formula for finding the area of rectangle

Reference: BEC PELC IV B 1.3.1Materials: textbooks and teachers manual, activity cards/sheets with rectangle figure,

cartolina, illustration board, pentel pen, chalkboard, manila paper, rulerValue: Self-discipline



1. Drill

Give: Kinesthetic Math exercises0forefinger and thumb together forming an O1right arm forward closed fist2left arm forward closed fist3arms closed towards the body4hand on waist5right hand on the chest

2. Review

How did you find the area of a square?Checking of assignment

3. Motivation

Game: Treasure huntingMaterials: Concrete objectsMechanics:- Form 4 groups of three members each.- When the teacher gives the signal to start the activity, the pupils will get all the

objects inside the box.

- The group which has the greatest number of objects collected from the box, wins thecontest

- (The teacher asks about the common size of objects collected from the box)(Rectangle)


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1. Presentation

The teacher will ask the pupils to draw a rectangle on the board.

- Look at the given figure.- What do you call the figure on the board?- Guide the pupils to identify the length and width of the rectangle.- What can you say about the length and width of a rectangle? Are they equal?

Aside from counting square units, let us find another way of getting the area of arectangle. (Present illustration like the one below.)

In our figure what is the length of our rectangle? 6 cm width? 4 cm

What shall we do with 6 and 4 to get 24?- Guide the pupils to find the area of the rectangle.

What shall we do with the length and width to find the area of a rectangle?

2. Guided Practice

a. Contest (by pairs)Mechanics

The teacher calls two pupils for every number.Teacher will flash figures like the one below.

Using the short cut method find the area of a rectangle (L x W)The player who gives first the correct answer, gets the point.

b. Find the area of the rectangle.1. 2.

Area (rectangle) = L x W orA (rectangle) = 4 x 6

= 24 cm2

6 cm

4 cm

3 cm

4 cm

15 cm

5 cm


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3. Complete the chart

Length Width Area

18m

30m

5m 4m

3. Generalization

How can you find the area of a rectangle?

- Multiply the length and the width.A = L x W

C. Application

Read, analyze, solve.

1. Mrs. Murcia has a carpet in the shape of a rectangle. The rug is 2 metres long and 3 metreswide. What is the area of the carpet?

2. The area of a rectangular lot is 104 m2. What is the length of the lot if it is 8m wide?

IV. Evaluation

A. Find the area of the rectangle.

1.

2.

3.

8 cm

6 cm

6 cm

6 cm

5 cm

4 cm


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4.

5.

B. Complete the chart

C. Solve each problem.

1. Mrs. Santos has a bed sheet in the shape of a rectangle. The bed sheet is 2 m long and 3 mwide. What is the area of the bed sheet?

2. The length and width of a sheet of paper are 10 cm and 5 cm respectively. What is the area?3. Mr. Abe is covering a wall with cork. A piece of cork is 20 cm wide and 25 cm long. What is

the area of a cork?4. A piece of fabric is shaped like a rectangle. The length of the fabric is 10 metres. The width is

4 metres. What is the area?5. What is the area of a city hall which is 130 m long and 98 m wide?

7 m

9 m

3 cm

4cm


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V. Assignment

A. Using the given length and width find the area.

1. L = 8 cmW = 3 cm

2. L = 5 cmW = 4 cm

3.

B. Solve the following problems.

1. Grandpas white house is 15 m long and 12 m wide. What is its area? 2. The medicine cabinet is 15 dm long and 12dm wide. Find the area.3. The ballroom plaza has a length of 25 m and a width of 20 m. What is its area?

Deriving a Formula for Finding the Area of Square


Cognitive: Derive a formula for finding the area of a square

Psychomotor: Tell a formula for finding the area of a squareUse the formula in finding the area of a squareAffective: Develop cooperation/teamwork


Skill: Deriving a formula for finding the area of a squareTelling a formula for finding the area of a square

Reference: BEC PELC IV B 1.3.2Materials: textbooks and teachers manual, activity cards/sheets with square figure,

cartolina, illustration board, pentel pen, chalkboard, manila paper, rulerValue: Teamwork



1. Drill/Review Have a game.

a. Identify the following objects on the table.1. books2. pencil3. paper4. pictures

3 m

2 m


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5. cards6. (square) bags7. (rectangle) bag8. bamboo stick9. rope

b. The teacher will ask different units of measure to be used in measuring the following:- What unit of measure will you use to measure a book? garden? table? distance from

Puerto Princesa City to Narra? (cm, m or km.)

2. Motivation

Give the following activities to the pupils.

a. Copy this drawing

a. Using two squares, group the flowers so there will be one flower in a section.

Answer


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1. Presentation

a. Present this figure.

Ask:

How many square units are there inside the figure?What can you say about its sides? (the same sides)How can you find the area of the square, aside from counting the square units?In the figure, how many square units are there in the side? (4 square units)If we use centimetre (cm) as our unit so one side is 4 cm.Have the pupils discover the formula for finding the area of a square.

4 cm

Present this figureb.

Ask: What is the side of the figure?What is the area of the figure, using the short cut formula?

A = S x S A = 3 x 3A = S

2 A = 9 cm

2

Area (square) = S x S orA (square) = S

2

A = 4 x 4 = 16 cm2or 16 square

centimetre

3 cm


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c. Find the area of a floor whose side is 5 mAsk: What is the area of the floor?

A = 5 m x 5 mA = 25 m

2

2. Guided Practice:

Activity I

a. Pupils will be divided into two groups: Team A and Team B. The teacher will giveinstruction to the pupils.

b. Teacher will give figures drawn on a manila paper.He will ask:

What is/are the given side/s?What is the formula for finding the area of the square?What is the area of the square?

1.

Those who can give most correct answers win.

Activity 2

Cooperative Learning

a. Rally Robin

- Pupils will be divided into triads.- They have to answer 3 questions.- The first group who got the correct answer will be the winner.

1)

5 m

3 cm

3 cm

4 m

4 m

5 m

2.

3.

4.

5.

2 cm

6 cm

3 cm


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2)

3)

4)

5)

- Questions (see Activity 1)- Teacher will give more figures/numbers.

3. Generalization

What can you say about the sides of a square?How do you find the area of a square?

Multiply the side by itself.A = S x S orA = S

2

1 cm

9 cm

8 cm

7 cm


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C. Application (Solve by pairs.)

a. Find the area of the figures.1) 2)

b. Find the missing number,

1) Figures Sides Area

A. 5 cm ______

B. 4 cm ______

C. 9 m

IV. Evaluation

1. Find the area.

2. Find the side of a square.

3. Father has a 25 m2garden. What is the side of his garden?

a. 5 m b. 4 m c. 3 m

4. The guest room in Mr. Estrellas house is in the shape of a square. One side measures 5metres. Find the area of the room.

5. Joy drew a picture on a square piece of paper. Each side of the paper is 18 centimetres.What is the area of the paper?

V. Assignment

A. Write your answer on your notebook.1. Draw a square with 81 cm

2. Give its side.

2. Draw a square with 49 cm2. Give its side.

B. Read the following problems, then solve.

1. A hall with a square floor has a side measuring 15 metres. What is the area of the floor?a. Draw a picture to find the answer.b. Solve the problem using the formula.c. Answer: ___________

2. Mr. Flores has a vegetable garden in the shape of a square with a side measuring 8 metres.What is the area of the garden?a. Draw a picture to find the answer.

6 cm

10 cm

4 m

3 cm

5 dm

?

A = 49 cm ? A = 4 cm


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b. Solve the problem using the formula.c. Answer: ___________

Solving Word Problem involving Area of a Rectangle


Cognitive: Solve word problem involving area of a rectanglePsychomotor: Give the length when width and area are given or give the width when the length

and area are givenAffective: Help one another in doing assigned duties


Skills: Solving word problem involving area of a rectangleFollowing the steps in problem solving

Reference: BEC PELC IV B.2.1Materials: textbook, chart, number wheelValue: Helpfulness



1. Drill

Basic multiplication facts.

2. Review

Find the area of the following rectangles.

c. L = 20 m d. L = 7 m e. L = 20 mW = 10 m W = 5 m W = 15 m

3. Motivation.

Ask pupils to go out in two groups. Give each group a metre stick, string and sticks. Askthem to make a rectangle 10 metres long and 7 metres wide. Ask: Who can give the area ofthis rectangle?

4 m

2 m

10 ma.

5 m

b.


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1. Presentation

a. Our room measures 12 metres long and 10 metres wide. Only Lyn and Lenie swept thefloor. What is the area of the room they swept? Stress the value of helping one another.

What is the shape of our room?

Rectangle. Why? It has length and width.How do we find the area?We multiply the length and the width.Lets write the mathematical sentence and solve. State the complete answer.

12 x 10 = N120 sq. m

What is the unit of measure? sq.mIs this the correct answer?

b. If your garden measures 9 metres long and its width is 8 metres, what is its area? Whatis the mathematical sentence?

A = 9 x 8 = 72 sq. m

c. What is the width of a garden which has an area of 96 sq. metres and a length of 12 sq.metres?

What are we solving for in the problem?What are given? Area96 sq. metres

Length12 metresWhat operation are we going to use?What is the number sentence?

96 12 = n

96 12 = 8

The final answer is 8 metres.Is the answer correct? Is it really the width? Why? Which is longer the width or thelength?

2. Guided Practice

Form groups of 10 members each. Solve each problem correctly. Write each digit of theanswer on each box that corresponds to the letter across and down.

8 7 5 sq m 3 0 sq. tiles2 0 8 sq. units 8 0 sq. units

9 0 sq. m 1 2 0 sq. units

sq. cm 9 6 sq. cm

Across.

1. Mr. Sison bought a piece of land which is 35 m long and 25 m wide. What is thearea?


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4. Mang Roy and his son were laying tiles on the kitchen floor. The length of thekitchen floor is 6 sq. tiles and the width is 5 sq. tiles. How many square tiles werelaid in all?

5. Dionie has a rose garden. It is 26 units long and 8 units wide. What is its area?

6. Harrys Math book is 10 sq. units long and 8 units wide. What is the area of his Mathbook?

7. Jumbos garden is 15 sq. units in length and 6 square units in width. How manysquare units is Jumbos garden?

8. What is the area of a page of a calendar which is 10 square units and length is 12square units?

9. A chocolate box measures 12 cm long and 8 cm wide. What is its area?

Down

2. What is the area of a box, when the length is 48 cm and the width is 15 cm.

3. My vegetable garden is 10 metres long and 5 metres wide. What is the area?

Working in Dyads.

1. What is the width of a rectangle with a length of 8 cm and an area of 96 square cm?

2. The area of a rectangle is 30 square cm. If the length is 6 cm, what is its width?

3. What is the width of a rectangle with a length of 12 cm and an area of 120 sq. cm?

4. The garden has an area of 60 sq. m If the length is 10 m what is the width?

5. The room has an area of 72 sq. m What is the width if the length is 12 metres?

3. Generalization

How do you solve problems involving area of a rectangle?

To solve problems involving area of a rectangle.

Multiply the length and the width.

If the length is unknown, divide the area by the width.

If the width is unknown, divide the area by the length.

C. Application

Read, analyze and solve

1. The movie theatre is 15 metres wide and 22 metres long. What is its area?

2. What is the area of the auditorium whose length is 35 metres and whose width is 32metres?

3. The playing field is 250 metres long and 100 metres wide. What is its area?

4. Mr. Samson a subdivision owner, donated a lot for a chapel measuring 15 metres by 25metres. What is the area of the site for the chapel?


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5. Mang Berto has a rice field which is 120 metres long and 95 metres wide. What is itsarea?

6. A piece of land with an area of 2425 sqm is 55 m long. How wide is the lot?

7. An auditorium with an area of 1120 sqm is 32 metres wide. How long is the auditorium?

8. The area of Mr. Reyes lot is 120 sqm. Mrs. Garcias lot is twice as big as Mr. Reyes.What is the area of Mrs. Garcias lot?

IV. Evaluation

Read, analyze and solve.

1. The area of the room is 108 sq. metres. If the length is 12 metres, what is its width?

2. Ressie sets a table for twelve people. The table is 9 units long and 6 units wide. What is thearea of the table?

3. The swimming pool is 12 units long and 8 units wide. How big is the swimming pool in squareunits?

4. The area of the park is 200 sq. units. If the width is 10 units, what is the length?

5. Mr. Hernandez added one more bathroom to their house. The bathroom is 4 units long and 3units wide. How big is the bathroom?

V. Assignment

Solve.

1. Tony made a chopping board which is 20 cm long and 15 cm wide. What is its area?2. Abdul made a banner for the program. The banner is 25 cm long and 18 cm wide. What is the

area of the banner?3. The area of a lot is 500 sq. metres. If the length is 25 metres, what is the width?4. A farmer has a ricefield which is 120 metres long and 92 metres wide. What is the area of this

land?5. The municipal plaza has a length of 48 metres and a width of 36 metres. What is its area?

Solving Word Problems involving Area of a Square


Cognitive: Solve word problems involving area of a square

Psychomotor: Tell what is asked, given, word clues and the operation to be usedTransform the word problem into a number sentence

Affective: Save an amount for the future


Skill: Solving word problems involving area of a squareReference: BEC PELC IV B.2.1.2Material: chartValue: Thrift


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1. DrillGive the most appropriate unit of measure for the following. (cm, m or km)

a. room b. coupon bond c. shoeboxd. toilet e. manila paper f. tableg. book h. cartolina i. fish pondj. distance from Pampanga to Manila

2. Review

Find the area of the following.

3. Motivation.

How much is your daily allowance? Are you saving a little amount from your dailyallowance? Who among you has a savings box? What do you do with the amount yousave? Why do we need to save some amount?


1. Presentation

a. Mario is a thrifty boy. Out of his savings, he was able to buy a handkerchief for his friend.The handkerchief has a side of 25 cm. What is the area?

DISCUSSION

What is the shape of the handkerchief? SquareWhat is asked? area of the handkerchiefWhat is given?What is the process to be used?

Who can give the number sentence?

25 x 25 = N How did you get the other 25?

Now let us multiply the numbers.1225

x 2512550_625 square centimetres

2 cm 3 cm

10 cm

12 cm 15 cm


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Is the answer correct? Did we answer the question in the problem?

b. If the area of a square parking lot is 100 square metres, what is the measurement of theside?

Show a cut-out graphing paper with 100 square units. Let us pretend that a smallsquare is equal to one metre?

Let us measure one side and the other side. How many square units? So what isthe answer to our problem? 10 metres

We can also solve the problem by thinking of the number which when we multiply byitself, will have a product of 100. What is that number? 10; so what is our completeanswer? 10 metres.

Let us try this problem. The area is 64 square m. What is the side?

What is asked? What is given?

What is the number that when multiplied by itself, will give 64?

What is the complete answer to our problem? 8 metres

2. Guided Practice

a. Working in Dyads.

1. The area of a parking lot is 144 sq. m. What is the side?2. A square mirror has a side of 49 cm. What is the area?3. What is the area of a table tray which has 48 cm on all sides?4. A teachers table has 45 cm on all sides. What is the area? 5. What is the area of a living room which measures a side of 15 m?

b. Form learning partners. One fast or average learner + slow learner. They will playWinners Take All as in MTB Channel 2.

1. Call two pairs of contestants.2. They will be asked to listen to a problem.3. Without using ballpen and paper they have to give the answer.


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4. The first to give the correct answer remains.5. The pair who remains will choose their opponent.6. Repeat the process until only one pair is left.

Questions:

1. A square shaped lawn is 5 sq. metres on its side. What is the area?2. A square mirror has a side of 30 cm. What is the area?3. A parking lot has a side of 20 m. What is the area?4. A table cloth has a side of 2 metres. What is the area?5. Nenes handkerchief has a side of 6 dm. What is the area?6. The area of a square lot is 100 square metres. What is the side?7. A square mirror has a side of 40 cm. What is the area?8. Mr. Araneta bought a square lot which measures 8 metres on one side.

What is its area?9. Mrs. Paguirigans handkerchief has a side of 30 cm. What is the area?10. Cielos handkerchief is a square. It is 50 centimetres on each side. What is

its area?

3. Generalization

How did we solve the problems involving area of a square?

To solve a one-step word problem involving the concept of area, follow the POLYAs problemsolving steps.

a. Understandb. Planc. Decided. Look Back

In solving for area just multiply the given side by itself.

In solving for a sidethink of a number which when multiplied by itself will give the area.

C. Application

Read, analyze and solve

1. A table runner measures 54 cm on all sides. What area of the table does it cover?2. What is the area of Deos board which has a side of 49 cm? 3. If the area of a handkerchief is 144 square cm, what is the side?4. What is the area of a handkerchief which has 35 cm on all sides? What will happen to the

area if you double the side?5. Mr. Cruz has a square vegetable garden with one side measuring 8 metres. If you add 2

more metres to the side what will be the area of the garden?

IV. Evaluation

Choose the letter of the correct answer.

1. The guest room in Mr. Santos house is square in shape. One side is 5 metres long. Findthe area of the room.

a. 25 sq. m c. 21 sq. mb. 20 sq. m d. 15 sq. m


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2. Mommy Rose bought a square birthday cake for her daughter Mariedeth. If the cakemeasures 45 centimetres on each side, what is the area of the cake?

a. 180 sq. cm c. 2 052 sq. cmb. 280 sq. cm d. 2 025 sq. cm

3. Sharons square vegetable garden measures 5 metres on one side. What is the area of thegarden?


4. A handkerchief measures 40 centimetres on each side. What is its area?


V. Assignment

Read and solve.

1. One side of a square table measures 120 centimetres. What is its area?2. Pilo put up a sari-sari store on a square lot in front of his house. The lot measures 12 m on each

side. Find the area.3. A plastic bag measures 60 cm on each side. What is the area?4. A square scarf measures 62 dm on its side. Find the area.5. Mr. Nicanor Tan ordered five boxes of square tiles. Each tile measures 45 cm on each side.

What is the area of one tile?6. Mr. Balangue bought a square lot which measures 15 metres on one side. What is its area?

lesson guide - gr. 3 chapter iv -measurement -area v1.0.pdf

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