Compute $(-144)\div 9$.
I want to find out how many times 9 goes into -144, or what number times 9 equals -144. I can use long division to do this, or I can try to use mental math. I know that 9 times 16 is 144, so 9 times -16 must be -144. Therefore, $(-144)\div 9 = -16$. 