All the solutions provided in McGraw Hill My Math Grade 3 Answer Key PDF Chapter 7 Lesson 5 Divide by 4 will give you a clear idea of the concepts.
McGraw-Hill My Math Grade 3 Answer Key Chapter 7 Lesson 5 Divide by 4
Math in My World
Example 1
The distance around a square window in Peter’s house is 12 feet. What is the length of each side?
Find 12 ÷ 4.
One Way: Use models.
Start with 12 counters. Circle 4 equal groups.
There are _______________ counters in each group. 12 ÷ 4 = _______________
So, the length of each side of the window is _______________ feet.
Another Way: Use repeated subtraction.
Subtract groups of 4 until you reach 0.
Count the number of times you subtracted.
Groups of ______________ were subtracted ______________ times.
So, 12 ÷ 4 = _______________.
Answer:
One way is:
12 ÷ 4 = 3
There are 3 counters in each group.
So, the length of each side of the window is 3 feet.
Another way is:
Subtract groups of 4 until you reach 0.
Count the number of times you subtracted.
Groups of 4 were subtracted 3 times.
So, 12 ÷ 4 = 3.
Example 2
An ostrich egg weighs 4 pounds. The total weight of the eggs in a nest is 28 pounds. How many ostrich eggs are there?
Helpful Hint
Multiplication is the inverse operation of division.
Find the unknown in 28 ÷ 4 = 
.
Draw an array. Then use the inverse operation, multiplication to find the unknown.
You know that ______________ × 4 = 28.
So, then 28 ÷ 4 or 
.
The unknown is ______________. There are ______________ ostrich eggs.
Answer:
Given that,
An ostrich egg weighs 4 pounds.
The total weight of the eggs in a nest is 28 pounds.
Know use the inverse operation, multiplication to find the unknown.
7 x 4 = 28
The unknown is 7.
Therefore There are 7 ostrich eggs.
Talk Math
Without dividing, how do you know that the quotient of 12 ÷ 3 is greater than the quotient of 12 ÷ 4?
Answer:
Without dividing we can by seeing the divisor.
If the divisor is less the quotient is more. If the divisor is more then the quotient is less.
So, the quotient of 12 ÷ 3 is greater than the quotient of 12 ÷ 4.
12 ÷ 3 = 4
Here 4 is the quotient.
12 ÷ 4 = 3
3 is the quotient.
The quotient of 12 ÷ 3 is greater than the quotient of 12 ÷ 4.
Guided Practice
Use counters to find how many are in each group.
Question 1.
8 counters
4 equal groups
_____________ in each group
So, 8 ÷ 4 = _____________.
Answer:
Given that,
8 counters and 4 equal groups.
So, 8 ÷ 4 = 2.
Therefore there are 2 in each group.
Question 2.
24 counters
4 equal groups
_____________ in each group
So, 24 ÷ 4 = _____________.
Answer:
Given that,
24 counters in 4 equal groups.
So, 24 ÷ 4 = 6.
Therefore there are 6 in each group.
Question 3.
Use repeated subtraction to find 20 ÷ 4.
So, 20 ÷ 4 = ______________.
Answer:
Given that,
Use the repeated subtraction to find the 20 ÷ 4
So, 20 ÷ 4 = 5.
Independent Practice
Use counters to find the number of equal groups or how many are in each group.
Question 4.
28 counters
4 equal groups
______________ in each group
So, 28 ÷ 4 = ______________, or 
.
Answer:
Given that,
28 counters into 4 equal groups.
28 ÷ 4 = 7.
or
Therefore there are 7 in each group.
Question 5.
4 counters
4 equal groups
______________ in each group
So, ____________ ÷ ____________ = ____________ or 
.
Answer:
Given that,
4 counters in 4 equal groups
4 ÷ 4 = 1.
or
Therefore there are 1 in each group.
Use repeated subtraction to divide.
Question 6.
8 ÷ 4 = _______________
Answer:
Divide 8 ÷ 4 using repeated subtraction.
8 – 4 = 4.
4 – 4 = 0.
So, 8 ÷ 4 = 2.
There are 2 in each group.
Question 7.
16 ÷ 4 = _______________
Answer:
Divide 16 ÷ 4 using repeated subtraction.
16 – 4 = 12.
12 – 4 = 8.
8 – 4 = 4.
4 – 4 = 0.
So, 16 ÷ 4 = 4.
Therefore there are 4 in each group.
Algebra Draw an array and use the inverse operation to find each unknown.
Question 8.
? × 6 = 24
÷ 4 = 6
? = ___________
= _____________
Answer:
We know that,
4 x 6 = 24.
24 ÷ 4 = 6.
? = 4.
The unknown is 24.
The array of 4 x 6 is
Question 9.
8 × ? = 32
32 ÷ 4 =
? = ____________
= _____________
Answer:
8 x 4 = 32.
32 ÷ 4 = 8.
? = 4.
The unknown = 8.
The array of 8 x 4 is
Problem Solving
Algebra Write a division sentence with a symbol for the unknown ¡n Exercises 10 and 11. Solve.
Question 10.
Gwen, Clark, Elvio, and Trent will be on vacation for 20 days. They are dividing the planning equally. How many days will Clark have to plan?
Answer:
Given that,
Gwen, Clark, Elvio, and Trent will be on vacation for 20 days.
They are dividing the planning equally.
The number of persons are 4.
So, 20 ÷ 4 = 5.
Therefore Clark have to plan for 4 days.
Question 11.
A bus has 32 pieces of luggage. If each person brought 4 pieces of luggage, how many people are on the trip?
Answer:
Given that,
A bus has 32 pieces of luggage.
If each person brought 4 pieces of luggage,
The number of people on the trip is 32 ÷ 4 = 8.
Therefore there are 4 people in each trip.
Question 12.
Mathematical PRACTICE Reason It costs $40 for 4 friends to ride go-carts for 1 hour. How much does it cost 1 person to ride for 2 hours?
Answer:
Given that,
It costs $40 for 4 friends to ride go-carts for 1 hour.
The cost for each person per 1 hour is $40 ÷ 4 = $10.
The cost of each person per 2 hours is $10 x 2 = $20.
Therefore the cost of each person per 2 hours is $20.
HOT Problems
Question 13.
Mathematical PRACTICE Find the Error Kendra wrote the two number sentences below to help her find 12 ÷ 4. Explain and correct her mistake.
4 + 8 = 2
S0, 12 ÷ 4 = 8.
Answer:
In the given question the two number sentences are mistake.
The correct sentence is
4 + 8 = 12.
So, 12 ÷ 4 = 3.
Question 14.
Building on the Essential Question How can an array help me divide?
Answer:
The array is the group of things arranged in the rows and columns. It is helped to divided the one number by another number. Rows represent the number of groups and columns represent the size of group.
McGraw Hill My Math Grade 3 Chapter 7 Lesson 5 My Homework Answer Key
Practice
Use counters to find how many are in each group.
Question 1.
8 counters
4 equal groups
_____________ in each group
So, 8 ÷ 4 = ____________.
Answer:
Given that,
8 counters in 4 equal groups.
So, 8 ÷ 4 = 2.
There are 2 in each group.
Question 2.
40 counters
4 equal groups
_____________ in each group
So, 40 ÷ 4 = ______________
Answer:
Given that,
40 counters in 4 equal groups.
So, 40 ÷ 4 = 10.
Therefore there are 10 in each group.
Question 3.
28 counters
4 equal groups
______________ in each group
So, 28 ÷ 4 = ______________
Answer:
Given that,
28 counters in 4 equal groups.
So, 28 ÷ 4 = 7.
Therefore 7 in each group.
Question 4.
12 counters
4 equal groups
______________ in each group
So, 12 ÷ 4 = ______________
Answer:
Given that,
12 counters in 4 equal groups.
So, 12 ÷ 4 = 3
Therefore there are 3 in each group.
Use repeated subtraction to divide.
Question 5.
24 ÷ 4 = ______________
Answer:
Divided 24 ÷ 4 using the repeated subtraction is
So, 24 ÷ 4 = 6.
Question 6.
16 ÷ 4 = ________________
Answer:
Divided 24 ÷ 4 using the repeated subtraction is
So, 24 ÷ 4 = 6.
Algebra Use the inverse operation to find each unknown.
Question 7.
____________ × 2 = 8
____________ ÷ 4 = 2
Answer:
Multiplication of 4 with 2 then you get 8.
4 x 2 = 8.
8 divided by 4 equal to 2.
8 ÷ 4 = 2.
The known is 8.
Question 8.
9 × ____________ = 36
36 ÷ 4 = _______________
Answer:
Multiplication of 9 with 4 then you get 36.
9 x 4 = 36
36 divided by 4 equal to 9.
36 ÷ 4 = 9
The unknown is 9.
Problem Solving
Write a division sentence to solve.
Question 9.
A boat rental shop has enough boats for 28 people to ride. Each boat seats 4 people. How many boats does the shop have?
Answer:
Given that,
A boat rental shop has enough boats for 28 people to ride.
Each boat seats 4 people.
The number of boats in the shop are 28 ÷ 4 = 7.
Therefore there are 7 boats in each shop.
Question 10.
Mathematical PRACTICE Explain to a Friend Ollie and 3 friends evenly shared 24 marbles. Kaitlyn and 2 friends evenly shared 18 marbles. Did Ollie or Kaitlyn’s friends get more marbles? Explain.
Answer:
Given that,
Friend Ollie and 3 friends evenly shared 24 marbles.
Number of persons are 4.
24 ÷ 4 = 6.
Ollie has 6 marbles.
Kaitlyn and 2 friends evenly shared 18 marbles.
Number of persons are 3.
18 ÷ 3 = 6.
Kaitlyn has 6 marbles.
Therefore both the ollie and Kaitlyn has same marbles that is 6.
Test Practice
Question 11.
Each minute, 4 gallons of water flow into a bathtub. How many minutes does it take for the bathtub to have 32 gallons of water?
(A) 6 minutes
(B) 7 minutes
(C) 8 minutes
(D) 9 minutes
Answer:
Given that,
Each minute, 4 gallons of water flow into a bathtub.
For 32 gallons of water.
32 ÷ 4 = 8.
Therefore there are minutes to take for the bathtub to have 32 gallons of water.
Option C is the correct answer.