Second graders will focus a majority of second grade developing an understanding of multi-digit addition and subtraction, and strategies for both. The key idea in second grade is the "ten-ness" of a number. That is that one ten is made up of ten ones, and one hundred is made up of ten tens. This place value understanding is critical to all of the math they will learn in the future. Here are some games that will help to reinforce these key concepts: