I use this in my classroom to help my students learn when to regroup in two digit by two digit subtraction problem. I use this as an assessment three times, but it doesn't have to be used for three days. At the end of my subtraction unit, my students were successful in determining when to regroup and solving the problems correctly. I have listed below the way I use this in my classroom. I broke it down by each day.
1. The first day I use it for my students to just answer the regrouping question. I will then check their answers before giving it back to them.
2. The second day they actually solve the problems. I don't check their work after this day.
3. The third day they use addition to check their problems. I have them write on sticky notes the addition problem to check their answers.