We have been practicing double-digit subtraction using base ten blocks this week. This helps us understand what is really happening in a subtraction problem. Sometimes we realized we had to “trade” in a ten for ten ones before we could start taking away blocks.
You can still use materials at home to help you visually understand subtraction problems, you just might need to be creative. For example, toothpicks could be longs and cheerios could be cubes. Drawing a picture of longs and cubes also helps at times.
Another great tool for practicing these problems is the National Library of Virtual Manipulatives (NLVM) for Pre-K- 2. There is a Base Blocks Subtraction practice section. You can follow the link above in this post, or find it in our blogroll on the sidebar.