Download Math-Module-4-Lesson-21

Module 4 Lesson 21
Explain the size of the product, and relate fraction and
decimal equivalence to multiplying a fraction by 1.
Stephen J. O’Connor
[email protected]
ccss5.com
Based upon lessons created by Common Core,Inc
•
Common Core
Standards
•
5.NF.5 Interpret multiplication as scaling (resizing), by:
•
a. Comparing the size of a product to the size of one factor on
the basis of the size of
the other factor, without performing the indicated multiplication.
•
b. Explaining why multiplying a given number by a fraction
greater than 1 results in a product greater than the given number
(recognizing multiplication by whole numbers greater than 1 as a
familiar case); explaining why multiplying a given number by a
fraction less than 1 results in a product smaller than the given
number; and relating the principle of fraction equivalence a/b =
(n×a)/(n×b) to the effect of multiplying a/b by 1.
5.NF.6 Solve real world problems involving multiplication of fractions
and mixed numbers, e.g., by using visual fraction models or equations
to represent the problem.
Learning
Targets
•
I can explain the size of the product, and relate
fraction and decimal equivalence to multiplying a
fraction by 1.
•
Multiply Decimals
•
Find Unit Conversion
•
Multi-step: Multiply fractions ond unit conversion
•
Explain the size of the product, and relate fraction
and decimal equivalence to multiplying a fraction
by 1.
•
Explain the size of the product, and relate fraction
and decimal equivalence to multiplying a fraction
by 1.
Sprint A
Sprint B
Fluency
Practice
How many feet in 1 yard?
Fluency
Practice
Express
yards as an improper fraction.
Fluency
Practice
Write an expression using the improper
fraction and feet then solve.
Fluency
Practice
How many qts in 1 gal?
Fluency
Practice
Express
gallons as an improper fraction.
Fluency
Practice
Write an expression using the improper
fraction and quarts then solve.
Fluency
Practice
How many inches in 1 foot?
Fluency
Practice
Express
feet as an improper fraction.
Fluency
Practice
Write an expression using the improper
fraction and inches then solve.
Fluency
Practice
How many cups in 1 pint?
Fluency
Practice
Express
pints as an improper fraction.
Fluency
Practice
Write an expression using the improper
fraction and cups then solve.
Application
Problem
Carol had
yard of ribbon. She wanted to use it
to decorate two picture frames. If she uses half
the ribbon on each frame, how many feet of
ribbon will she use for one frame? Use a tape
diagram to show your thinking.
Concept
Development
Write a multiplication expression
for this problem.
Problem 1
Concept
Development
Work with a partner to find the product of 2
halves and 3 fourths.
Problem 1
Concept
Development
Let’s draw an area model to verify our
solution.
Problem 1
Concept
Development
How does the size of the product compare
to the size of the original fraction?
Problem 1
Concept
Development
Work with a partner to solve. One multiplies
while the other draws a model
Problem 1
Concept
Development
Show some other fraction multiplication
expressions involving 3 fourths that would give
us a product that is equal in size to 3 fourths.
Problem 1
Concept
Development
Is this true? Turn and talk.
Problem 1
Concept
Development
Is this true? Write a multiplication
sentence to show your thinking.
Problem 1
Concept
Development
Give the product
Problem 2
Concept
Development
What are some other ways to
express
?
Problem 2
Concept
Development
Is this
true?
Problem 2
Concept
Development
How can we change 3 fifths to a decimal?
Problem 2
Concept
Development
Work with a partner to express 3 fifths
as a decimal.
Problem 2
Concept
Development
Work with a partner to express 3 fifths
as a decimal.
Problem 2
Concept
Development
Write as a decimal.
Problem 2
Concept
Development
Could we have easily renamed fourths as
tenths? Why or why not? Turn and talk.
Problem 2
Concept
Development
Is 25 hundredths the only decimal name for 1
fourth? Is there another unit that would rename
fourths as a decimal? Turn and talk.
Problem 2
Concept
Development
Is 25 hundredths the only decimal name for 1
fourth? Is there another unit that would rename
fourths as a decimal? Turn and talk.
Problem 2
Concept
Development
Work with a neighbor to express as a decimal,
showing your work with multiplication sentences.
One of you multiply by
, and the other multiply
by
. Compare your work when you’re done.
Problem 2
Concept
Development
Think about . Are eighths a unit we can
express directly as a decimal, or do we need to
multiply by a fraction equal to 1 first?
Problem 2
Concept
Development
What fraction equal to 1 will help us rename
eighths? Discuss with your neighbor.
Problem 2
Concept
Development
How would you express
neighbor.
as a decimal? Tell a
Problem 2
Concept
Development
How would you express
neighbor.
as a decimal? Tell a
Problem 2
Concept
Development
How would you express
as a decimal?
Problem 2
Concept
Development
How would you express
as a decimal?
Problem 2
Concept
Development
How would you express
as a decimal?
Problem 2
Practice
Concept
Development
Review
Practice
Activate
Knowledge
✔
Check
Understanding
Sprint A
Learning Targets
Teamwork
Application
Problem
Fluency Practice