CPM Homework Help : CC2 Problem 3-46

Find the value of each expression below. Change any subtraction problem to an equivalent addition problem. Draw a diagram with $+$ and $-$ tiles to justify your answer.

$5-7$
Hint (a):
The equivalent addition problem is $5+(-7)$ .

$-5+(-7)$
Hint (b):
The drawing should look something like this:
$-----$
$-------$

$-5+7$
Answer (c):
$2$
Remember to draw your diagram.

$-5-(-7)$
Hint (d):
For the expression $-5-(-7)$ , draw three pairs of zeros ( $+$ & $-$ ). Then add $5$ negatives. Then take out $7$ negatives. Remove any zeros. What is left?