Lesson 29 Objective: Connect division by a unit fraction to division by 1 tenth and 1 hundredth By...

Lesson 29Objective: Connect

division by a unit fraction to division by 1 tenth

and 1 hundredth

By the end of the lesson, you will be able to…

5th Grade Module 4– Lesson 29K. Clauson

Count By Fractions

Divide Whole Numbers By Unit Fractions & Fractions by

Whole Numbers

Application Problem

Fernando bought a jacket for $185 and sold it for 1 ½ times what he paid. Marisol spent 1/5 as much as Fernando on the same jacket but sold it for ½ as much as Fernando did. How much money did Marisol make? Explain your thinking using a diagram.

Problem 1= 7 ÷ 0.1

• Read the division expression using unit form.

• Rewrite the expression using a fraction.

• What question does this division expression ask us?

• Let’s start with just 1 whole. How many tenths are in 1 whole?

• Think of this another way…

Concept Development

How many tenths are in 7?7 is one tenth of what number?

7 ÷ 1/10

7 ones divided by 1 tenth

10 tenthsThere are _____ tenths in 7 wholes.

70

Seven is one-tenth of what number?

Problem 2= 7.4 ÷ 0.1

• Rewrite this division expression using a fraction for the divisor.

• Compare this problem to the last one… what do you notice?

7.4 ÷ 1/10

There still are 7 wholes, but now there are also 4 more tenths.There are 74 tenths instead of 70 tenthsWe can ask ourselves, 7.4 is 1 tenth of what number?

Problem 2= 7.4 ÷ 0.1

• We already know this part…• There are _____ tenths in 7 wholes.

• There are _____ tenths in 4 tenths.

• So how many tenths are in 7 and 4 tenths?

70

4

74

74 tenths ÷ 1 tenth = 74 tenths

Try these problems!

• 6 ÷ 0.1=

• 6.2 ÷ 0.1=

• 9 ÷ 0.1=

• 9.8 ÷ 0.1=

• 12 ÷ 0.1=

• 12.6 ÷ 0.1=

60

629

098120126

Problem 3a = 7 ÷ 0.01

• Read this expression

• Rewrite the division expression using a fraction for the divisor

• We can think of this as finding how many hundredths are in 7.

• Will our quotient be greater than or less than our last problem?

7 ÷ 1/100

Greater because we are counting unitsthat are much smaller, so there will bemore of them.

Problem 3a = 7 ÷ 0.01

• Before we think about how many hundredths are in 7 wholes, let’s find out how many hundredths are in 1 whole.• There are ______ hundredths in 1 whole.• There are ______ hundredths in 7 wholes.

• So 7 ÷ 1/100 = 700• 7 ÷ 0.01 = 700

100700

Problem 3b = 7.4 ÷ 0.01

• What is the whole in this division expression?

• How many hundredths are in 7 wholes?

• How many hundredths are in 4 tenths?

• How many hundredths are in 7.4?

• Asked another way, if 7.4 is 1 hundredth, what is the whole?

7 and 4 tenths

700

40

740

740

Problem 3c = 7.49 ÷ 0.01

• Work with a partner to solve this problem. Be prepared to explain your thinking.

7.49 ÷ 1/100 = 7497.49 ÷ 0.01 = 749

Final Problems!

• How many hundredths are in 6?

• How many hundredths are in 6.2?

• 6.02?

• 12.6?

• 12.69?

600

620

602

1260

1,269

Get Ready to Finish theProblem Set on Your Own!

Work on Problem Set 29.

You will have 10 minutes to work!

-------------------------------------------------------------------Fast finishers:

- Math Center Activities- choice boards, extra Sprint challenge

- CML packets/ worksheets

- Problem Solving pages

5th Grade Module 4– Lesson 29K. Clauson

5th Grade Module 4- Lesson 29K. Clauson

LET’S DEBRIEF

• Take 2 minutes to check your answers with your partner.

• Let’s share any insights you had while solving these problems.

5th Grade Module 4– Lesson 29K. Clauson

EXITTICKETLESSON 29