Subtraction is the operation of finding the difference between two numbers. It tells us how much remains when a quantity is taken away, or how far apart two numbers are.

To subtract, align the numbers by place value and subtract each column from right to left. If the top digit is smaller than the bottom digit, borrow (regroup) from the next column to the left.

Word problems use clue words like "how many more," "how many fewer," "difference," "remaining," and "left over." Subtraction is the inverse of addition, meaning you can check your answer by adding: if a − b = c, then c + b should equal a.