Subtracting Integers Summary

1. Rewrite as an addition sentence
2. Apply addition rules

1. Rewrite as an addition sentence

a) Change subtraction operand to an addition operand or a plus sign
b) Change the sign of the following number to its opposite

This process is referred to as "addition of the opposite".


Example 1
5 – 9 = would become 5 + (-9)

Example 2
-9 - 4 =
-9 + (-4) =
Notice the first number, -9, was not changed.

Example 3
-4 – (-8) =
-4 + 8 =

Example 4
7 – (-5) =
7 + 5 =



Subtraction Review -

Rewrite subtraction of integers as an _____________________ sentence.

Then follow the _________________ rules of integers.


Addition Review

Add two positive integers and the answer will be ________________ .

Add two negative integers and the answer will be ____________________.

Add two integers with different signs by ___________________ the __________ values.

Then, the sign of the answer is determined by the integer with the _______________ absolute value.

Practice Problems: Rewrite each problem as addition and solve.
1. -23 - 23 =
2. -19 - 29 =
3. 42 - (-62) =
4. 34 – 46 =
5. -29 - 12 =
6. -57 - (-67) =
7. -88 - (-88) =
8. -30 - 49 =
9. 24 - (-32) =
10. 124 - 453 =
11. - 211 - 49 =
12. 59 - (- 87) - (- 5) =
13. (-4) - (-3) - 2 - (-1) =
14. (-18) - 5 - 23 - ( - 4) =
15. 45 - (-23) - 29 - (- 39) =










Answers -

Subtraction Review -

Rewrite subtraction of integers as an addition sentence.

Then follow the addition rules of integers.


Addition Review -

Add two positive integers, and the answer will be
positive.


Add two negative integers and the answer will be negative.

Add two integers with different signs by subtracting. the absolute values.

Then, the sign of the answer is determined by the integer with the largest absolute value.

Practice Problems (Note – The parentheses around a negative number are for clarity; they are not mandatory.)

1. -23 - 23 = - 46

2. -19 - 29 = - 48

3. 42 - (-62) = 104

4. 34 - 46 = - 12

5. -29 - 12 = - 41

6. -57 - (-67) = 10

7. -88 - (-88) = 0

8. -30 - 49 = - 79

9. 24 - (-32) = 56

10. 124 - 453 = - 329

11. - 211 - 49 = - 260

12. 59 - (- 87) - (- 5) = 151

13. (-4) - (-3) - 2 - (-1) = - 2

14. (-18) - 5 - 23 - ( - 4) = - 42

15. 45 - (-23) - 29 - (- 39) = 78