... 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 add 35 + 200 + 31 to calculate atotal ... get to a friendly number first, and then adding hundreds, tens, and ones. For example, students might calculate 556 –189 by:• adding 11 to 189 to get to 200; then• adding 300 to 200 to get to ... 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...