2nd grade

Once students learn how to subtract with regrouping, they can apply those skills to numbers of any size!  For more on regrouping (how and why it works), see lesson on Subtraction (with Regrouping, 2-1 and 2-2 digits).

The first step in subtracting multi-digit numbers is setting the problem up vertically, making sure that the place values are lined up (ones to ones, tens to tens, etc).

Once you have learned to add with regrouping, you can add numbers of any size. The process that you use with multi-digit numbers is the same as the process used with two-digit numbers, you just keep moving over, place value by place value.