This lesson includes a script for teaching students how to build the "teen" numbers, including discussion questions.
The questions are one of the most important parts of the activity since it leads the students to explain their thinking, which will solidify their number sense (which we all know has huge effects down the road!)
Included are blackline masters for a two-sided math mat. One side contains one ten frame, and the second side contains two ten frames. They can be laminated and written on with dry erase markers, or any small counters, coins, or beans could be used as markers on top of the board.