This handy Spectrum Math Grade 7 Answer Key Chapter 1 Lesson 1.3 Subtraction as an Inverse Operation provides detailed answers for the workbook questions.
Spectrum Math Grade 7 Chapter 1 Lesson 1.3 Subtraction as an Inverse Operation Answers Key
Subtraction is the same as the process of adding the additive inverse, or opposite, of a number to another number.
7 – 4 = 7 + (-4)
Write an equivalent equation using the additive inverse.
Question 1.
a. 8 – 3 = ____
Answer: 5
8 – 3 = 8 + (-3) = 5
Subtraction is the same as the process of adding the additive inverse, or opposite, of a number to another number.
b. 9 – 2 = _____
Answer: 7
9 – 2 = 9 + (-2) = 7
Subtraction is the same as the process of adding the additive inverse, or opposite, of a number to another number.
Question 2.
a. 12 + (-7) = ____
Answer: 5
12 + (-7) = 12 – 7 = 5
Subtraction is the same as the process of adding the additive inverse, or opposite, of a number to another number.
b. 8 + (-12) = ____
Answer: -4
8 + (-12) = 8 – 12 = -4
Subtraction is the same as the process of adding the additive inverse, or opposite, of a number to another number.
Question 3.
a. 52 – 13 = ____
Answer: 39
52 – 13 = 52 + (-13) = 39
Subtraction is the same as the process of adding the additive inverse, or opposite, of a number to another number.
b. 23 – 10 = ____
Answer: 13
23 – 10 = 23 + (-10) = 13
Subtraction is the same as the process of adding the additive inverse, or opposite, of a number to another number.
Question 4.
a. 67 + (-11) = ____
Answer: 56
67 + (-11) = 67 – 11 = 56
Subtraction is the same as the process of adding the additive inverse, or opposite, of a number to another number.
b. 45 + (-6) = ____
Answer: 39
45 + (-6) = 45 – 6 = 39
Subtraction is the same as the process of adding the additive inverse, or opposite, of a number to another number.
Question 5.
a. 30 – 15 = ____
Answer: 15
30 – 15 = 30 + (-15) = 15
Subtraction is the same as the process of adding the additive inverse, or opposite, of a number to another number.
b. 74 – 23 = ____
Answer: 51
74 – 23 = 74 + (-23) = 51
Subtraction is the same as the process of adding the additive inverse, or opposite, of a number to another number.
Question 6.
a. 3 + (-56) = ____
Answer: -53
3 + (-56) = 3 – 56 = -53
Subtraction is the same as the process of adding the additive inverse, or opposite, of a number to another number.
b. 62 + (-32) = ____
Answer: 30
62 + (-32) = 62 – 32 = 30
Subtraction is the same as the process of adding the additive inverse, or opposite, of a number to another number.
Question 7.
a. 87 – 85 = ____
Answer: 2
87 – 85 = 87 + (-85) = 2
Subtraction is the same as the process of adding the additive inverse, or opposite, of a number to another number.
b. 54 – 20 = _____
Answer: 34
54 – 20 = 54 + (-20) = 34
Subtraction is the same as the process of adding the additive inverse, or opposite, of a number to another number.
Question 8.
50 + (-17) = ____
Answer: 33
50 + (-17) = 50 – 17 = 33
Subtraction is the same as the process of adding the additive inverse, or opposite, of a number to another number.
b. 41 + (-12) = ____
Answer: 29
41 + (-12) = 41 – 12 = 29
Subtraction is the same as the process of adding the additive inverse, or opposite, of a number to another number.
Question 9.
a. 89 – 57 = ____
Answer: 32
89 – 57 = 89 + (-57) = 32
Subtraction is the same as the process of adding the additive inverse, or opposite, of a number to another number.
b. 46 – 40 = _____
Answer: 6
46 – 40 = 46 + (-40) = 6
Subtraction is the same as the process of adding the additive inverse, or opposite, of a number to another number.
Question 10.
a. 96 + (-20) = ____
Answer: 76
96 + (-20) = 96 – 20 = 76
Subtraction is the same as the process of adding the additive inverse, or opposite, of a number to another number.
b. 94 + (-90) = ____
Answer: 4
94 + (-90) = 94 – 90 = 4
Subtraction is the same as the process of adding the additive inverse, or opposite, of a number to another number.
Question 11.
a. 83 – 67 = ____
Answer: 16
83 – 67 = 83 + (-67) = 16
Subtraction is the same as the process of adding the additive inverse, or opposite, of a number to another number.
b. 98 – 34 = ____
Answer: 64
98 – 34 = 98 + (-34) = 64
Subtraction is the same as the process of adding the additive inverse, or opposite, of a number to another number.
Question 12.
a. – 76 + (-20) = ____
Answer: -96
– 76 + (-20) = – 76 – 20 = -96
Subtraction is the same as the process of adding the additive inverse, or opposite, of a number to another number.
b. 90 + (-76) = _________
Answer: 14
90 + (-76) = 90 – 76 = 14
Subtraction is the same as the process of adding the additive inverse, or opposite, of a number to another number.