Lesson 16: I can solve word
problems using decimal
operations
5th Grade Module 1 – Lesson 16
Concept Development
Take out your Problem Set (1.F.50) and we will work Problem 1 on
your Problem Set together. We will use a tape diagram to solve.
Mr. Frye distributed $126 equally among his 4 children for their
weekly allowance.
a. How much money did each child receive?
Who and What is this problem about?
Mr. Frye’s Money
Let’s identify our variables (unknowns).
Draw a bar to represent Mr. Frey’s money.
Mr. Frye’s Money
Let’s read the problem sentence by sentence and adjust our diagram to match
the information in the problem. Let’s read the first sentence together.
5th Grade Module 1 – Lesson 16
Click to next slide…
What is the important information in the first sentence? Turn and Talk.
Mr. Frye distributed $126
equally among his 4___________
children
_____________
for their weekly allowance.
$126
Mr. Frye’s Money
How can we represent this information on the diagram?
We can use a bracket on top of the bar and label it.
How many children share the $126?
How can we represent this information?
*note to teacher: use the lesson plan to prompt5th
students
Grade Module 1 – Lesson 16
Mr. Frye distributed $126
equally among his 4___________
children
_____________
for their weekly allowance. How much money did each
$126
child receive?
Mr. Frye’s Money
What is the question?
?
How much money did each child receive?
What is the unknown in this problem? How will we represent it in our diagram?
Turn and talk.
We are trying to find out the amount of money one of Mr. Frye’s children
received for allowance. We should put a question mark inside one of the
parts. Make sure you label your diagram just like I am.
5th Grade Module 1 – Lesson 16
Mr. Frye distributed $126
equally among his 4___________
children
_____________
for their weekly allowance.
$126
Mr. Frye’s Money
?
Let’s make a unit statement about our diagram. How many unit bars are equal to $126?
4 units is the same as $126
How can we find the value of ONE unit? Turn & Talk.
We can use division because we have a whole that we are sharing equally.
What is the equation that will give us the amount that each child receives?
$126 ÷ 4 = _____
Solve and express your answer in a
complete sentence.
1 unit = $ 31.50
5th Grade Module 1 – Lesson 16
$126
Mr. Frye’s Money
$31.50
Look at part b of question 1 and solve using a tape diagram.
b).
John, the oldest child, paid his siblings to do his chores. If John pays his allowance
equally to his brother and two sisters, how much money will each of his siblings have
received in all?
$31.50
John’s money
?
Click to reveal solution.
$31.50 ÷ 3 = ?
From Mr. Frye = $31.50
3 tens ÷ 3 + 15 tenths ÷ 3
From John
= $10.50
1 ten + 5 tenths
Total
=$42.00
10.5 = $10.50
5th Grade Module 1 – Lesson 16
Let’s try #4 in your Problem Set!
I will guide you through the problem.
Brandon mixed 6.83 lbs. of cashews with 3.57 lbs. of pistachios.
After filling up 6 bags that were the same size with the mixture,
he had 0.35 lbs. of nuts left. What was the weight of each bag?
Use a tape diagram and show your calculations.
Read the problem. Identify the variables (who & what) and draw a bar.
Brandon’s cashews/pistachios
5th Grade Module 1 – Lesson 16
Brandon mixed 6.83
lbs. of cashews with _______________________
3.57 lbs. of pistachios.
_____________________
After filling up 6 bags that were the same size with the mixture,
he had 0.35 lbs. of nuts left. What was the weight of each bag?
Use a tape diagram and show your calculations.
Read the first sentence.
What is the important information in this sentence? Tell your partner.
6.83
3.57
Brandon’s cashews/pistachios
How can we represent this information on our tape diagram?
We will have two parts inside the bar. Will they be equal in size?
No! The cashews are about twice the size!
5th Grade Module 1 – Lesson 16
Lets read the next sentence. How will we represent this part of the problem? Turn & Talk.
Brandon mixed 6.83 lbs. of cashews with 3.57 lbs. of pistachios.
After filling up 6 bags that were the same size with the mixture,
he had 0.35 lbs. of nuts left. What was the weight of each bag?
Use a tape diagram and show your calculations.
6.83 + 3.57 =
10.4
Brandon’s cashews/pistachios
b
b
b
b
b
b
left
0.35
I used the same bar but added the cashews & pistachios together (10.4lbs.) and split the
bar up between the 6 bags with the mixture plus the 0.35lbs leftover.
Draw & Label
on your sheet!
5th Grade Module 1 – Lesson 16
What is the question? Where should we put our question mark?
?
Brandon mixed 6.83 lbs. of cashews with 3.57 lbs. of pistachios.
After filling up 6 bags that were the same size with the mixture,
he had 0.35 lbs. of nuts left. What was the weight of each bag?
Use a tape diagram and show your calculations.
6.83 + 3.57 =
10.4
Brandon’s cashews/pistachios
b
b
b
b
b
b
left
0.35
How will we find the value of 1 unit in
our diagram? Turn & Talk.
Perform your calculations and state
your answer in a complete sentence.
(10.4 – 0.35) ÷ 6 =
10.05 ÷ 6 =
1.675 lbs.
5th Grade Module 1 – Lesson 16
Problem Set Work
Complete questions 2 and 3 on the Problem Set
worksheet. Use a tape diagram and calculations
to solve.
5th Grade Module 1 – Lesson 16
Debrief
• In question 3, how did you represent the
information using the tape diagram?
• How did the tape diagram in 1(a) help you
solve 1(b)?
• Look at 1(a) and 5(b). How are the questions
different? Does the difference in the
questions affect the calculation of the
answer?
5th Grade Module 1 – Lesson 16
Exit Ticket Time!
5th Grade Module 1 – Lesson 10