“Today you used different methods to subtract 2 two-digit numbers.”
“You solved in ways that make sense to you, and you used base-ten blocks to take away different amounts.”
“How was subtracting a two-digit number from a two-digit number the same as subtracting a one-digit number from a two-digit number?” (It was the same because we still had to think about subtracting ones. Sometimes you have to decompose a ten if you need more ones.)
"How was it different?” (When you subtract a two-digit number, you have to think about subtracting tens too. The number you are subtracting is bigger because it's a two-digit number.)
"How did working together with a partner or a group help you understand different ways to subtract two-digit numbers?"