All the solutions provided in McGraw Hill My Math Grade 1 Answer Key PDF Chapter 4 Review will give you a clear idea of the concepts.

Question 1.
count back  Explanation:
I drew a circle around the first number line as it correctly shows the difference of 6 and 6.

Question 2.
fact family
7 + 3 = 10 3 + 7 = 10
3 + 7 = 10 4 + 6 = 10
10 – 7 = 3 5 + 5 = 10
10 – 3 = 7 8 + 2 = 10 Explanation:
A fact family is a set of facts that have same numbers
I drew circle around the set of number sentences that are called fact family.

Question 3.
8 + 3 = 11 8 + = 11 Explanation:
I drew a circle around the number sentence that correctly shows the missing addend.

Question 4.  Explanation:
I drew circle around the number sentence in which the arrow mark points towards difference of the numbers
5 is difference of 6 and 1.

Concept Check

Count back to subtract.

Question 5.
7 – 3 = ____
4

Explanation:
7 – 3 =
Start at 7
Count back 3
6, 5, 4
So, 7 – 3 = 4.

Question 6.
9 – 2 = ____
7

Explanation:
9 – 2 =
Start at 9
Count back 2
8, 7
So, 9 – 2 = 7. Question 7.
11 – 2 = ____ Explanation:
11 – 2 =
Start at 11
Count back 2 by jumping back
I react at 9
So, 11 – 2 = 9.

Question 8.
10 – 1 = ____ Explanation:
10 – 1 =
Start at 10
Count back 1 by jumping back
I react at 9
So, 10 – 1 = 9.

Add the doubles facts. Then subtract.

Question 9.
6 + 6 = ____
12 – 6 = ____
6 + 6 = 12
12 – 6 = 6

Explanation:
6 + 6 = 12 is a doubles fact
So, 12 – 6 = 6
The related subtraction fact is 12 – 6 = 6.

Question 10.
8 + 8 = ____
16 – 8 = ____
8 + 8 = 16
16 – 8 = 8

Explanation:
8 + 8 = 16 is a doubles fact
So, 16 – 8 = 8
The related subtraction fact is 16 – 8 = 8.

Add and subtract. Complete the fact family.

Question 11.  Explanation:
I used the numbers 3, 5 and 8 to write the fact family
The sentences are 3 + 5 = 8, 5 + 3 = 8, 8 – 3 = 5 and 8 – 5 = 3.

Question 12.
5 + = 12
12 – 5 = 5 + = 12
12 – 5 = Explanation:
I wrote the missing addend by subtracting
12 – 5 = 7
So, 5 + 7 = 12.

Question 13.
9 + = 14
14 – 9 = 9 + = 14
14 – 9 = Explanation:
I wrote the missing addend by subtracting
14 – 9 = 5
So, 9 + 5 = 14.

Problem Solving

Question 14.
Paige writes two related facts using these numbers. What related facts could she have written?
____ + ____ = ____
____ – ____ = ____ 8 + 4 = 12
12 – 8 = 4

Explanation:
Paige writes two related facts using these numbers
12, 8, 4
The related facts are 8 + 4 = 12, 4  8 = 12, 12 – 8 = 4 and 12 – 4 = 8
So, the two related facts that Paige writes are 8 + 4 = 12 and 12 – 8 = 4.

Question 15.
Jayson caught 15 fish. Ashlyn caught 7 fish. How many more fish Jayson catch than Ashlyn?
____ – ____ = ___ fish 15 – 7 = 8

Explanation:
Jayson caught 15 fish
Ashlyn caught 7 fish
Subtract to find
15 – 7 =
Count back
Start at 15
Count back 7
14, 13, 12, 11, 10, 9, 8
So, 15 – 7 = 8
Therefore, 8 more fish Jayson caught than Ashlyn.

Test Practice

Question 16.
Cris has 14 jump ropes. What doubles fact shows the number of jump ropes Cris has?
(A) 7 + 8 = 14 jump ropes
(B) 7 + 7 = 14 jump ropes
(C) 14 – 5 = 9 jump ropes
(D) 6 + 6 = 12 jump ropes
(B) 7 + 7 = 14 jump ropes

Explanation:
Cris has 14 jump ropes
The doubles fact is 7 + 7 = 14.

Reflect

Show the ways to subtract

Essential Question?
What strategies can I use to subtract?

Count Back
12, ___, ___, ___
12 – 3 = ___
12, 11, 10, 9
12 – 3 = 9

Explanation:
Start at 12
Count back by 3
11, 10, 9
So, 12 – 3 = 9.

Use Doubles
10 + 10 = ___
20 – 10 = ___
10 + 10 = 20
20 – 10 = 10

Explanation:
10 + 10 =20 is the doubles fact
So, 20 – 10 = 10
The related subtraction fact is 20 – 10 = 10.

Make a ten So, 17 – 8 = ___ Explanation:
17 – 8 =
Make ten
8 = 7 and 1
= 17- 7 – 1
= 10 – 1
= 9
So, 17 – 8 = 9.

5 + = 14
14 – 5 = 5 + = 14
14 – 5 = 