Question

Help me with 12 and 13, please! The question is, “Write a subtraction number sentence for the models shown.” Please explain too!

Answer 1

- 8 -(-4) = -4. The shaded buttons with - in them are negative. Cross then mount is subtract because they are “taking away”

3 - (-6) = -9. They started with 3 buttons. In order to subtract negatives when there,are none (or not enough, you have to bull negatives out of thin air ( bypassing zeros) so you add zero pains (as many as you need to subtract the negative.

A zero pair is two buttons that add to zero: one positive and one negative