It’s easier to do this than you might think 👇 Really we just need students to realize the pattern of regrouping. For subtraction, that is when there is not enough ones, we need to exchange a ten into 10 ones. That means the number in the tens place is going to decrease by 1 and the number in the ones place is going to increase by 10. Students discover these patterns when they solve problems with base ten blocks. You want to give them a mix of problems where they need to regroup and they don’t n