Module 4 Lesson 14

Module 4 Lesson 14Find areas by decomposing into rectangles or completing composite figures to form rectangles

Skip countingLets skip count by 4s to 40. 481216202428323640Skip countingLets skip count by 6s to 60. 6121824303642485460Skip countingLets skip count by 7s to 70. 7142128354249566370Skip countingLets skip count by 9s to 90. 9182736455463728190Multiply by 86 x 8 = _______Lets skip count UP by 8s to solve. 81624324048Lets skip count DOWN by 8s starting at 80. 807264564848Multiply by 88 x 8 = _______Lets skip count UP by 8s to solve. 816243240485664Lets skip count DOWN by 8s starting at 80. 807264

64Multiply by 89 x 8 = _______Lets skip count UP by 8s to solve. 81624324048566472Lets skip count DOWN by 8s starting at 80. 807248PATTERN SHEET

Find the area

On your white board or notebook, write a number sentence to show the area of theshaded rectangle. Write a number sentence to show the area of the un-shaded rectangle. 5 x 2 = 10 square units or 2 x 5 = 10 square units3 x 2 = 6 square units or 2 x 3 = 6 square units___ sq. Units + ____ sq. Units = ___ sq. Units 10616Find the areaOn your white board or notebook, write a number sentence to show the area of theshaded rectangle. Write a number sentence to show the area of the un-shaded rectangle. 4 x 3 = 12 square units or 3 x 4 = 12 square units2 x 2 = 4 square units or 2 x 2 = 4 square units___ sq. Units + ____ sq. Units = ___ sq. Units 12416

Find the areaOn your white board or notebook, write a number sentence to show the area of theshaded rectangle. Write a number sentence to show the area of the un-shaded rectangle. 2 x 6 = 12 square units or 6 x 2 = 12 square units2 x 4 = 8 square units or 4 x 2 = 8 square units___ sq. Units + ____ sq. Units = ___ sq. Units 12820

Find the areaOn your white board or notebook, write a number sentence to show the area of theshaded rectangle. Write a number sentence to show the area of the un-shaded rectangle. 4 x 4 = 16square units or 4 x 4 = 16 square units2 x 2 = 4 square units or 2 x 2 = 4 square units___ sq. Units + ____ sq. Units = ___ sq. Units 16420

Problem of the day

Break apart the shaded figureinto 2 rectangles. Then, add to findthe area of the shaded figure below. Subtract the area of the unshaded rectangle fromthe area of the large rectangle to check your answer.

Concept Development Choose an appropriate Method for Find the Area of a composite shape.What two strategies did we learnlast week to find the area of a non-rectangular shape?

Make sure everyone has a problem set

Look at problem 1(a)

What is the unknown Width?

Label that on your figure.

Then, write an equation used to find the area of each of thesmaller rectangles.

What is the area of the top rectangle?

The bottom rectangle?

On your problem set, write the equation to find the area of the whole figure.

WHAT IS THE TOTAL AREA?19 square centimeters!Problem 2: solve a word problem involving the area of non-rectangular shapes.Sierra has a piece of fabric that is 8 feet long and 5 feet wide. She cuts out a rectangular piece that measures 3 feet by 2 feet. How many square feet of fabric does Sierra have left? Draw and label Sierras fabric.

How big is the piece that Sierra cuts out?

Draw the piece of fabric that Sierra cuts out dont forget to labelthe measurements. (THUMBS UP WHEN YOURE DONE)

What is the best way for us to find the area of the remaining fabric?

Write an equation to find the area of the original piece of fabric.

Beneath what you just wrote write an equation to find the area of the piece of fabric Sierra just cut out. What is the area of the piece that is cut out?

What expression tells us the area of the remaining fabric?

40 6.

How much fabric does Sierra have left?

34 square feet! PROBLEM SET