... strategy because of the regrouping required to subtract 6 tens from 3 tens. However, an adding-on strategy might be used: Add 35 to 465 to get to 500, add 200 to get to 700, add 31 to get to 731, and ... encourage students to represent mathematical ideas, to select appropriate tools and strategies, to communicate and reflect on strategies and solu-tions, and to make connections between mathematical ... knew that I needed to find the difference between 226 and 148. So I started at 148 and added on 2 to get to 150. Next, I added on 50 to get to 200. Then I added on 26 to get to 226. I figured...