How to Subtract Integers: Keep Change Change Practice
Use Keep Change Change to rewrite subtraction as addition
How to Subtract Integers: Keep Change Change Practice
Use Keep Change Change to rewrite subtraction as addition
Math - Grade 6-8
- 1
Use Keep Change Change to solve: 7 - 12
Rewrite the subtraction problem as an addition problem before solving.
Keep 7, change subtraction to addition, and change 12 to -12. The problem becomes 7 + (-12), which equals -5. - 2
Use Keep Change Change to solve: -4 - 9
Keep -4, change subtraction to addition, and change 9 to -9. The problem becomes -4 + (-9), which equals -13. - 3
Use Keep Change Change to solve: 6 - (-8)
Subtracting a negative number is the same as adding its opposite.
Keep 6, change subtraction to addition, and change -8 to 8. The problem becomes 6 + 8, which equals 14. - 4
Use Keep Change Change to solve: -10 - (-3)
Keep -10, change subtraction to addition, and change -3 to 3. The problem becomes -10 + 3, which equals -7. - 5
Use Keep Change Change to solve: 15 - 21
When adding numbers with different signs, subtract their absolute values and keep the sign of the number with the greater absolute value.
Keep 15, change subtraction to addition, and change 21 to -21. The problem becomes 15 + (-21), which equals -6. - 6
Use Keep Change Change to solve: -18 - 6
Keep -18, change subtraction to addition, and change 6 to -6. The problem becomes -18 + (-6), which equals -24. - 7
Use Keep Change Change to solve: 3 - (-14)
Change the second number to its opposite after changing the minus sign to a plus sign.
Keep 3, change subtraction to addition, and change -14 to 14. The problem becomes 3 + 14, which equals 17. - 8
Use Keep Change Change to solve: -25 - (-11)
Keep -25, change subtraction to addition, and change -11 to 11. The problem becomes -25 + 11, which equals -14. - 9
A submarine is at a depth of -40 meters. It descends 15 more meters. Write and solve an integer subtraction expression for the new depth.
Descending means the depth becomes more negative.
The expression is -40 - 15. Using Keep Change Change, it becomes -40 + (-15), which equals -55. The submarine is at -55 meters. - 10
The temperature was -6 degrees in the morning. By evening, the temperature was 9 degrees lower. Write and solve an integer subtraction expression for the evening temperature.
The expression is -6 - 9. Using Keep Change Change, it becomes -6 + (-9), which equals -15. The evening temperature was -15 degrees. - 11
Find the missing value: 12 - (-5) = ___
A minus sign followed by a negative number changes to addition of a positive number.
Keep 12, change subtraction to addition, and change -5 to 5. The problem becomes 12 + 5, which equals 17, so the missing value is 17. - 12
Find the error in this work and correct it: -8 - (-10) = -8 + (-10) = -18
In Keep Change Change, the second number changes sign.
The error is that -10 was not changed to its opposite. Using Keep Change Change, -8 - (-10) becomes -8 + 10, which equals 2.