This writing activity has eight problems that have been completed incorrectly. Its up to your students for find the errors and explain why the answers are wrong. Use all eight problems as a worksheet or use one question at a time for bell work/exit slip/time filler. The problems cover subtracting decimals, multiplying fractions, finding the area of a triangle and a circle, and proportions. I used this as an end of the year activity for my 7th graders. They had fun trying to find “my” mistakes.