Subtracting Integers Worksheets

Teach the rule "subtracting is adding the opposite" on the board, with two or three examples, then hand out the page. Ten to fifteen minutes is enough for 20 problems. Ask students to rewrite each problem as an addition in the work space before answering, even when they think they can do it in their heads. Review with the answer key and have them redo any problem where the answer's sign looks off.

The hardest case is subtracting a negative, which turns into adding a positive. Children also confuse the minus sign of subtraction with the negative sign of a number, which is why the second number appears in parentheses. Answers land on both sides of zero, so a number line is still handy. This follows adding integers and leads straight into multiplying and dividing them, then into algebra.

Start with the −10 to 10 Range until students can rewrite as addition without hesitation, then move to −20 to 20 and −100 to 100. The default is −20 to 20. Use 12 problems if each takes a while. For fluency, pick 30 and set a ten-minute goal. Mark the problems that subtract a negative with a star to see which ones need more work.

How do I explain subtracting a negative?

Take away a debt and you are better off. Or use the rule: change the minus to a plus and flip the sign of the second number. So 5 − (−3) becomes 5 + 3, which is 8.

Should students always rewrite as addition?

It works every time and is the standard method, so yes at first. Once they see the pattern they can do it in their heads. The work space beside each problem has room for the extra line.

Why do I see parentheses around some numbers?

They separate the subtraction sign from the sign of the number. 5 − (−3) is much easier to read than 5 − −3. Students may drop them in their own working once they understand.