# McGraw Hill My Math Grade 3 Chapter 11 Lesson 4 Answer Key Solve Mass Problems

All the solutions provided in McGraw Hill My Math Grade 3 Answer Key PDF Chapter 11 Lesson 4 Solve Mass Problems will give you a clear idea of the concepts.

## McGraw-Hill My Math Grade 3 Answer Key Chapter 11 Lesson 4 Solve Mass Problems

Math in My World

Example 1

The bucket balance shows the mass of one marker. What is the mass of 5 markers?

Find the unknown. 8 × 5 = ____________.
A bucket balance can be used to determine mass.

Use mass weights on one side of the balance and the object on the other side. When the sides are balanced, the objects have the same mass.

You can also use repeated addition.
3 + 8 + 8 + 8 + 8 = 40

Five markers are 8 grams each. So multiply.
8 × 5 = ____________
The unknown is ____________ grams.
So, the mass of 5 markers is ____________ grams.
Five markers are 8 grams each.
8 × 5 = 40 grams.
The unknown is 40 grams.
So, the mass of 5 markers is 40 grams.

Example 2

What is the total mass of the two pieces of fruit? Write an equation with a letter for the unknown. Then solve.

216 + 132 = f ← unknown
216 + 132 = _____________ grams
The unknown is _____________.
So, the two pieces of fruit have a combined mass of 348 grams.
The mass of apple = 216 grams
The mass of the banana = 132 grams
216 + 132 = f
348 = f
216 + 132 = 348 grams
The unknown is 348 grams.

Talk Math

Explain how you solved Exercise 2.

By using the addition operation we can find the total mass of the apple and banana.
216 + 132 = f
348 = f
216 + 132 = 348 grams

Guided Practice

Algebra Write an equation with a letter for the unknown Then solve.

Question 1.
What is the mass of 9 buttons?

The mass of 1 box = 4 grams
The mass of 9 buttons = 4 × 9 = 36 grams
Thus the mass of 9 buttons = 36 grams

Question 2.
What is the mass of 1 jack?

The mass of 6 jacks = 30 grams
The mass of 1 jack = 30/6 = 5 grams

Independent Practice

Algebra Write an equation with a letter for the unknown. Then solve.

Question 3.
What is the mass of two of these books?

The mass of 1 book = 363 grams
The mass of 2 books = 363 × 2 = 726 grams

Question 4.
The golf ball has a mass of 45 grams. What is the mass of the baseball?

The golf ball has a mass of 45 grams.
The mass of golf ball and baseball = 190 grams
190 – 45 = 145 grams
So, the mass of the baseball is 145 grams.

Question 5.
What is the mass of one of these dominoes?

The mass of 6 dominoes = 66 grams
The mass of 1 dominoes = 66/6 = 11 grams

Algebra Find each unknown.

Question 6.
kilograms × 9 = 63 kilograms
The unknown is ______________.
kilograms × 9 = 63 kilograms
= 63/9
= 7 kilograms
So, the unknown is 7 kilograms

Question 7.
392 grams + grams = 523 grams
The unknown is ______________.
392 grams + grams = 523 grams
= 523 grams – 392 grams
= 131 grams
So, the unknown is 131 grams.

Question 8.
932 grams – grams = 149 grams
The unknown is ______________.
932 grams – grams = 149 grams
= 932 grams – 149 grams
= 783 grams
So, the unknown is 783 grams

Question 9.
60 kilograms ÷ = 6 kilograms
The unknown is ______________.
60 kilograms ÷ = 6 kilograms
= 60/6
= 10
So, the unknown is 10.

Problem Solving

Question 10.
A bucket balance shows that 2 rocks have a total mass of 732 grams. When 1 rock is removed, the bucket balance shows that the remaining rock is 428 grams. What is the mass of the rock that was removed?
Given,
A bucket balance shows that 2 rocks have a total mass of 732 grams.
When 1 rock is removed, the bucket balance shows that the remaining rock is 428 grams.
732 – 428 = 304 grams
Thus the mass of the rock that was removed is 304 grams.

Question 11.
A student has a mass of 34 kilograms. An adult has a mass of 56 kilograms. What is the difference in mass between the student and adult?
Given,
A student has a mass of 34 kilograms.
An adult has a mass of 56 kilograms.
56 – 34 = 22 kilograms
Thus the difference in mass between the student and adult is 22 kilograms

Question 12.
Mathematical PRACTICE Identify Structure A penny has a mass of about 3 grams. About how many grams would one dollar’s worth of pennies be? Write an equation with a letter for the unknown. Then solve.
A penny has a mass of about 3 grams.
1 dollar = 100 pennies
100 × 3 = 300 pennies

HOT Problems

Question 13.
Mathematical PRACTICE Be Precise One button has a mass of 3 grams. What is the mass of one pencil?

Given,
One button has a mass of 3 grams.
Mass of 7 buttons = 7 × 3 = 21 grams
3 + 2x = 21
2x = 21-3
2x = 19
x = 19/2
x = 9.5 grams
Thus the mass of one pencil = 9.5 grams

Question 14.
Building on the Essential Question When do you think it would be best to estimate the mass of an object and when would it be best to get an exact measure?
When two objects are in the balancing measure then it is better to find the exact measure of the object.
If you have to measure the mass of the object using arithmetic operations then it is best to estimate the mass of the object.

### McGraw Hill My Math Grade 3 Chapter 11 Lesson 4 My Homework Answer Key

Practice

Algebra Write an equation with a letter for the unknown. Then solve.

Question 1.
What is the mass of 2 boxes of raisins?

The mass of 1 box = 42 grams
The mass of 2 boxes = 42 × 2 = 84 grams

Question 2.
The scissors have a mass of 90 grams. What is the mass of the stapler?

Given,
The scissors have a mass of 90 grams.
540 grams – 90 grams = 450 grams
Thus the mass of the stapler is 450 grams.

Algebra Solve for the unknown.

Question 3.
511 kilograms + = 720 kilograms
= _______________ kilograms
511 kilograms + = 720 kilograms
= 720 kilograms – 511 kilograms
= 209 kilograms

Question 4.
90 grams ÷ = 10 grams
= ________________
90 grams ÷ = 10 grams
= 90/10
= 9

Question 5.
grams – 138 grams = 704 grams
= ________________
grams – 138 grams = 704 grams
= 704 + 138
= 842 grams

Question 6.
× 20 kilograms = 80 kilograms
= ________________
× 20 kilograms = 80 kilograms
= 80/20
= 4

Problem Solving

Question 7.
Melinda’s pair of ski boots and skis have a mass of 6 kilograms. What is the mass of one ski boot and one ski?
Given,
Melinda’s pair of ski boots and skis have a mass of 6 kilograms.
6/2 = 3
The mass of one ski boot and one ski is 3 kilograms.

Question 8.
A full bag of oatmeal has a mass of 560 grams. Cooper uses 80 grams of oatmeal to make breakfast for his family. What is the mass of the remaining oatmeal?
Given,
A full bag of oatmeal has a mass of 560 grams.
Cooper uses 80 grams of oatmeal to make breakfast for his family.
560 – 80 = 480 grams
The mass of the remaining oatmeal is 480 grams.

Question 9.
Each bag can hold a mass of 3 kilograms. Wade has 24 kilograms of fruit to divide equally. How many bags will he need?
Given,
Each bag can hold a mass of 3 kilograms.
Wade has 24 kilograms of fruit to divide equally.
24 ÷ 3 = 8
Thus he will need 8 bags.

Question 10.
Mathematical PRACTICE Use Number Sense Each of the four girls on Chantelle’s relay team got a swimming medal. One medal has a mass of 16 grams. What is the total mass of the relay team’s medals?
Each of the four girls on Chantelle’s relay team got a swimming medal. One medal has a mass of 16 grams.
We have to use the multiplication operation here.
4 × 16 = 64 grams
So, the total mass of the relay team’s medals is 64 grams.

Test Practice

Question 11.
Jennifer’s cats eat 2 kilograms of food per month. How much food do the cats eat in 8 months?

(A) 4 kilograms
(B) 10 kilograms
(C) 14 kilograms
(D) 16 kilograms