complete the equation for this model.

Explanation:

Step1: Identify the starting and ending points

The arrow starts at 10 and ends at -15.

Step2: Write the subtraction equation

We know that starting - change = ending. Here, the starting - point is 10, and we are moving to - 15. So the change is what we need to subtract from 10 to get - 15. Let the number to be subtracted be $x$. Then $10 - x=-15$. Solving for $x$, we get $x = 10-(-15)=10 + 15 = 25$. The equation is $10-25=-15$.

Answer:

$10 - 25=-15$