This activity goes along with the Harcourt math series (2005) Grade 2, Chapter 9, however, the material is just as good to cover the same skill in any series. The level of interactivity depends on the purpose of the activity. For example, in some activities the purpose is to be able to identify the amount rather than create it, so in that case the activity is not interactive. There are, however, many interactive activities. This file has 67 pages and focuses on introducing subtraction with regrouping, and includes mental math (subtracting tens and counting back one or two), regrouping tens as ones, 2 digit subtraction, and problem solving-choosing the operation.