What if the expression starts with a negative value?
1 In the example below, we’ve applied the Commutative Property and then the Additive Inverse Property to rewrite an addition expression as subtraction.
Start here: |
Apply the Commutative Property: |
Apply the Additive Inverse Property: |
||
(+ -4 7) |
→ |
(+ 7 -4) |
→ |
(- 7 4) |
−4 + 7 |
7 + −4 |
7 − 4 |
2 What will the first Circle evaluate to? 3 The second Circle? 3 The third Circle? 3
3 What do you Notice about these three Circles? What do you Wonder?
4 Look at the worksheet you just completed. Why is there an additional step in rewriting the addition expressions above?
5 In the table below, draw another example like the one above to show how we can rewrite more complex addition expressions as subtraction.
Start here: |
Apply the Commutative Property: |
Apply the Additive Inverse Property: |
||
(+ ) |
→ |
( ) |
→ |
( ) |
+ |
Try it out
Rewrite addition as subtraction, and subtraction as addition.
−50 + 5 = |
−8 + 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.