Question

use the number line to help solve the problem.
subtract -3 -3.
0
3
6
-6

Explanation:

Step1: Recall subtraction rule

Subtracting a number is same as adding its opposite: $a - b = a + (-b)$. So, $-3 - 3 = -3 + (-3)$.

Step2: Use number line

Start at -3. To add -3, move 3 units to the left (since we add a negative number, direction is left on number line). Moving 3 left from -3: $-3 - 3 = -6$.

Answer:

-6