confidential 1 area and perimeter grade 4. confidential 2 let’s warm up : fill in the blanks:...
TRANSCRIPT
CONFIDENTIAL 2
Let’s warm up :
Fill in the blanks:
1) ____ gram (g) = 43,000 milligrams (mg)
2) ____ kilogram (kg) = 79,000 grams (g)
3) 75 gram (g) = _____ milligrams (mg)
4) 69 kilogram (kg) = _____ grams (g)
CONFIDENTIAL 3
Let’s review what we did in the previous chapter
MASS: It is the amount of matter that makes up an object.The mass of a math book is 1 kilogram.
Customary Units are used in US. Metric Units are used by most countries.
Metric Units of Mass
1 gram (g) = 1,000 milligrams (mg)
1 kilogram (kg) = 1,000 grams (g)
Simple Conversion Tables
CONFIDENTIAL 4
Review
Convert grams to milligrams
To change to a smaller unit, multiply.
Example: How many milligrams is 4 grams?
We are given,
4 grams = __ milligrams 4 x 1,000 = 4,000
4 grams = 4,000 milligrams
4 grams is equal to 4,000 milligrams .
CONFIDENTIAL 5
Review
Convert milligrams to grams
To change to a Larger unit, divide.
Example: How many grams is 5,000 milligrams ?
We are given,
5,000 milligrams = __ grams5,000 ÷ 1000 = 5
5,000 milligrams = 5 grams
5,000 milligrams is equal to 5 grams.
CONFIDENTIAL 6
Review
Convert kilograms to grams
To change to a smaller unit, multiply.
Example: How many grams is 4 kilograms?
We are given,
4 kilograms = __ grams 4 x 1,000 = 4,000
4 kilograms = 4,000 grams
4 kilograms is equal to 4,000 grams .
CONFIDENTIAL 7
Review
Convert grams to kilograms
To change to a Larger unit, divide.
Example: How many kilograms is 5,000 grams ?
We are given,
5,000 grams = __ kilograms5,000 ÷ 1000 = 5
5,000 grams = kilograms
5,000 grams is equal to 5 kilograms.
CONFIDENTIAL 8
Today we will learn about the Area and perimeter
PERIMETER: It is the distance around a figure.
Area and perimeter are geometric measurements used to measure plane figures.
The perimeter
of the triangle is
3 cms.
1 cm
1 cm
1 cm
CONFIDENTIAL 9
AREA: is the number of square units needed to cover a plane figure.
2 cm
2 cm
The area of the square is 4 cms2.
Use a formula
Area of the square= side x side = 2cm x 2cm=.4 square centimeters
(cm2)
CONFIDENTIAL 10
PERIMETER: is computed by adding the lengths of the figure's sides.
For example:We see a hexagon.
2 cm
3 c
m3 c
m
We are supposed to find the perimeter of the hexagon.
CONFIDENTIAL 11
2 cm
3 c
m3 c
m
Add the lengths of the hexagon's sides.
Perimeter (P)
= 2 cm + 3 cm + 3 cm + 2 cm + 3 cm + 3 cm
= 16 cm
The perimeter of the given hexagon is 16 cm.
CONFIDENTIAL 12
AREA: is computed by counting the number of square units or use a formula.
Counting the squares1
cm
1 cm
Count the number of shaded centimeter squares.
There are 6 square centimeters (cm2).
CONFIDENTIAL 13
1 cm
1 cm
Use a formula
Multiply the length times the width to find the area.
Area of the rectangle= length x width= 2cm x 3 cm=.6 square centimeters
(cm2)
CONFIDENTIAL 14
Area of a complex figure
Find the area of the green portion
1 cm
1 cm
STEP1:
Divide the figure into rectangle or square.
CONFIDENTIAL 15
STEP2:
Find the area of each smaller figure.Area of green rectangle
= 3 x 6 = 18 cm2
Area of blue rectangle = 4 x 2 = 8 cm2
STEP3:
Add the area of both smaller figures.Area of the shaded portion
= 18 cm2 + 8 cm2
= 36 cm2
CONFIDENTIAL 18
Assignment
Find the perimeter of the given figures:
2 cm
2 cm
1 cm
1 cm
1 cm
1)
2)
2 cm
4 cm
3)
1 cm4)
CONFIDENTIAL 19
Find the area of the given figures:
2 cm
2 cm
5) 2 cm
4 cm
6)
5 cm
5 cm
7) 3 cm
7 cm
8)
CONFIDENTIAL 21
Very Good!Let's Review
PERIMETER: It is the distance around a figure.
Area and perimeter are geometric measurements used to measure plane figures.
The perimeter
of the triangle is
3 cms.
1 cm
1 cm
1 cm
CONFIDENTIAL 22
Review
AREA: is the number of square units needed to cover a plane figure.
2 cm
2 cm
The area of the square is 4 cms2.
Use a formula
Area of the square= side x side = 2cm x 2cm=.4 square centimeters
(cm2)
CONFIDENTIAL 23
ReviewPERIMETER: is computed by adding the
lengths of the figure's sides.
For example:We see a hexagon.
2 cm
3 c
m3 c
m
We are supposed to find the perimeter of the hexagon.
CONFIDENTIAL 24
Review
2 cm
3 c
m3 c
m
Add the lengths of the hexagon's sides.
Perimeter (P)
= 2 cm + 3 cm + 3 cm + 2 cm + 3 cm + 3 cm
= 16 cm
The perimeter of the given hexagon is 16 cm.
CONFIDENTIAL 25
Review
AREA: is computed by counting the number of square units or use a formula.
Counting the squares
1 cm
1 cm
Count the number of shaded centimeter squares. There are 6 square centimeters (cm2).
Use a formula
Multiply the length times the width to find the area. Area of the rectangle
= length x width= 2cm x 3 cm=.6 square centimeters (cm2)