Lesson 14: I can strategize to solve multi-term problems.

advertisement
5th Grade Module 4– Lesson 14
K. Clauson
Time to Sprint!
Multiply a fraction and a whole number
Fractions as Whole
Numbers
I’ll say a fraction. You say it as a division
equation and give the quotient.
4 halves
4÷2=2
Application Problem
Solve by drawing a rectangular fraction model and
writing a multiplication sentence.
Beth had 1/4 box of candy. She ate 1/2 of the candy.
What fraction of the whole box does she have left?
Extension: If Beth decides to refill the box, what
fraction of the box would need to be refilled?
Application Problem
Concept Development
Problem 1
Jan had 3/5 pan of crispy rice treats. She sent
1/3 of the treats to school. What fraction of
the whole pan did she send to school?

This problem is different than the ones we saw yesterday.
Now Jan has 3 fifths instead of 1 fraction unit of treats
(Remember unit fractions are 1/2, 1/3, 1/4)

Before we find 1/3 of Jan’s 3/5, let’s visualize this.



If there are 3 bananas, how many would 1/3 of the bananas
be?
What is 1/3 of 3 pens?
What is 1/3 of 3 books?
So, then, what is
1/3 of 3 fifths?
Concept Development
Problem 1
Jan had 3/5 pan of crispy rice treats. She sent
1/3 of the treats to school. What fraction of
the whole pan did she send to school?
1/3 of 3 fifths equals 1 fifth
Let’s draw an
area model to
prove your
thinking!
Use Interwrite tools to draw the rectangular fraction model!
Concept Development
Problem 1
Jan had 3/5 pan of crispy rice treats. She sent
1/3 of the treats to school. What fraction of
the whole pan did she send to school?
1/3 of 3 fifths equals 1 fifth
Problem 2
Jan had 3/4 pan of crispy rice treats. She sent
1/3 of the treats to school. What fraction of the
whole pan did she send to school?
1/3 of 3 fourths = 1 fourth
What do you think the answer for 1/3 of 3 fourths will be?
Work with a neighbor to solve one third of 3 fourths.
One of you can write draw the area model, while the
other writes a matching number sentence.
Problem 2
Jan had 3/4 pan of crispy rice treats. She sent
1/3 of the treats to school. What fraction of the
whole pan did she send to school?
Look back at the two problems we just solved.
If 1/3 of 3 fifths is 1 fifth and 1/3 of 3 fourths is 1 fourth,
what then is 1/3 of 3 eighths?
1/ 3 of 3 tenths?
1 tenth
1/3 of 3 hundredths?
1 hundredth
1/4 of 4 fifths?
1 fifth
1/2 of 2 fifths?
1 fifth
1/4 of 4 sevenths?
1 seventh
Problem 3:
𝟏/𝟐 × 𝟒/𝟓
Let’s draw a rectangular fraction model to confirm our thinking.
We need to find 1 half of 4 fifths.
If this were 1 half of 4 bananas, how
many bananas would we have?
How can you use this thinking to
help you find 1 half of 4 fifths?
Turn and talk.
1 half of 4 fifths is 2 fifths
Problem 3:
𝟏/𝟐 × 𝟒/𝟓
What patterns do you notice in
our multiplication sentences?
Turn and talk.
As we are modeling the rest of our problems,
let’s see if this pattern continues.
Problem 4
3/4 of Benjamin’s garden is planted in vegetables. Carrots
are planted in 1/2 of his vegetable section of the garden.
How much of Benjamin’s garden is planted in carrots?
1/2 x 3/4  1/2 of 3/4
Use Interwrite tools to draw the rectangular fraction model!
Problem 5:
𝟑/𝟒 of 𝟏/𝟐
Use Interwrite tools to draw the rectangular fraction model!
Problem 6
Mr. Becker, the gym teacher, uses 3/5 of his kickballs in class.
Half of the remaining balls are given to students for recess.
What fraction of all the kickballs is given to students for
recess?
Let’s draw a tape diagram!
Get Ready to Finish the
Problem Set on Your Own!
Start working on Lesson 14 Problem Set
You will have 10 minutes to work.
Try your Best!
----------------------------------------------------------------------------------------------Fast finishers:
-
Math Center Activities- choice boards, extra Sprint challenge
-
CML packets/ worksheets
-
Problem Solving pages
5th Grade Module 4– Lesson 13
K. Clauson
• 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 14
K. Clauson
EXIT
TICKET
LESSON 14
5th Grade Module 4– Lesson 14
K. Clauson
Download