This is a very basic question that I am having some difficulty grasping. When I do the long division for -101 / 13, my first step is -7 which comes out to -91 and so I have left -10. Shouldn't this be where the calculation stops? One of the thoughts I had was that as -13 is smaller than -10, I should go one step further and subtract -13 from -10 to get +3. and that's why the mod is 3. If that is correct, could someone please explain why? If that is incorrect, could someone please explain how we get 3 instead of 10? Thanks for any help.