From Adding to Subtracting
1 Under each Circle of Evaluation, write the equivalent arithmetic expression.
(+ 10 -3) |
= |
(- 10 3) |
+ |
= |
2 What will the first Circle evaluate to? The second Circle?
3 What do you Notice? What do you Wonder?
Did you know that adding −3 is the same as subtracting 3?
4 Under each Circle of Evaluation, write the equivalent arithmetic expression.
(+ 24 -21) |
= |
(- 24 21) |
+ |
= |
5 What will the first Circle evaluate to? The second Circle?
6 In the table below, fill in the blanks to demonstrate how adding a negative produces the same result as subtracting a positive. Then write the equivalent arithmetic expression for each of your Circles.
(+ 30 -5) |
= |
(- ) |
+ |
= |
− |
7 This time, we’ve completed the subtraction Circle of Evaluation. You fill in the equivalent addition Circle of Evaluation.
(+ ) |
= |
(- 2 10) |
+ |
= |
− |
Practice
Rewrite addition as subtraction, and subtraction as addition.
30 − 12 = 30 + −12 |
24 + −4 = |
100 − 101 = |
= 6 − 18 |
= 0 + −12 |
= 6 − 36 |
These materials were developed partly through support of the National Science Foundation, (awards 1042210, 1535276, 1648684, 1738598, 2031479, and 1501927). 
Bootstrap by the Bootstrap Community is licensed under a Creative Commons 4.0 Unported License. This license does not grant permission to run training or professional development. Offering training or professional development with materials substantially derived from Bootstrap must be approved in writing by a Bootstrap Director. Permissions beyond the scope of this license, such as to run training, may be available by contacting contact@BootstrapWorld.org.