Once your child understands regrouping, the written subtraction method is just a tidy routine: go column by column from the right, and borrow when the top digit is too small. Here is the whole thing, with a step-by-step tool.
There are two parts to subtraction with borrowing, and they are easy to mix up. The first is the idea: what borrowing actually means, which you build with bundles of ten or base-ten blocks. The second is the written routine: the neat column-by-column method you do on paper. This guide is about that second part, the pencil-and-paper method, and it assumes your child already has a feel for the idea.
Do the concept first: If borrowing still feels like a mystery to your child, start with the hands-on version before this one. Our guide on subtraction with regrouping builds the idea with objects your child can move. Once "borrow a ten" means something real, the written steps below become a simple habit instead of a magic trick.
The written method is just one rule, repeated: work one column at a time, starting from the right, and if the top digit is smaller than the bottom digit, borrow ten from the next column to the left. That is the entire routine. Everything else is neatness.
Let us subtract 52 minus 37. We will go one column at a time and say each step out loud, the way you want your child to.
The step that trips up almost every child is borrowing when the next column is a zero. You cannot take a ten from a zero directly, so the borrow has to travel one more column to the left, turning the zero into a nine along the way. It sounds fiddly in words, but the pattern is always the same.
Say "9 fills in" for the zeros: When a borrow crosses zeros, each zero it passes turns into a 9. Teaching that little phrase, "the zeros fill in with nines," gives your child a checkable pattern instead of a scary special case. The stepper above shows this happening if you try a problem like 1000 minus 1.
Faced with 2 on top and 7 below, a child often just does 7 minus 2 because it is easier, and writes 5. The result looks reasonable but it is wrong. This is the single most common subtraction error. The fix is the borrow: you never flip the columns, you make the top big enough first. Watching the stepper do it correctly a few times cements the habit.
After borrowing, kids often subtract the tens column using the original top digit instead of the reduced one. In 52 minus 37, the tens must be 4 minus 3, not 5 minus 3, because a ten was already lent to the ones. Crossing out the old digit and writing the new one above it keeps this honest.
Just like long division, most wrong answers come from digits drifting out of their columns, not from bad arithmetic. Grid paper, or a lined notebook turned sideways, keeps ones over ones and tens over tens so nothing gets subtracted from the wrong place.
They are the same thing. Older worksheets say "borrowing," newer ones say "regrouping." You are regrouping one ten into ten ones so the top number has enough to subtract from.
Two-digit borrowing usually starts in second grade, and three-digit and borrowing across zeros come in third and fourth grade. Children reach these at different times, and that is normal.
Because it is easier and avoids the borrow. Seeing 2 on top and 7 below, they do 7 minus 2. The fix is to make the top digit big enough by borrowing first, and never to flip the columns. Practicing with a step-by-step tool that always borrows correctly helps break the habit.
You cannot take a ten from a zero, so the borrow travels one more column to the left. Each zero it passes becomes a nine, and the first non-zero digit drops by one. For example, in 304 minus 158, the borrow reaches the hundreds, the tens zero becomes nine, and the ones can finally take their ten.
Add the answer back to the number you took away. If it equals the number you started with, the subtraction is correct. In 52 minus 37 equals 15, checking 15 plus 37 gives 52, so it is right.