Math practice guide
How to Review a Worksheet with an Answer Key
When an answer is wrong, go back through the work before looking at the next problem. Find the first step to change, then try the problem again.
Last reviewed 2026-08-07.
Check a few problems at a time
Review a short group before the same mistake spreads across the page. The key shows final answers, so use the student’s written work to find what happened.
Find the first step to change
For 27 + 15, an answer of 32 may mean the extra ten was missed. Check 7 + 5 = 12, write 2 in the ones place, carry 1 ten, and then add the tens to get 42.
Retry without copying
Cover the key and solve the problem again. If the same step is still difficult, create a fresh worksheet for that skill rather than copying the final answer.