lesson 29 objective: connect division by a unit fraction to division by 1 tenth and 1 hundredth by...
TRANSCRIPT
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