Students will construct their own meanings and pictures of numbers as they count dots and find different dominoes, and write addition and subtraction sentences to match. The students will build their reasoning and number skills as they solve mystery domino puzzles. The hands-on activities actively engage students in doing mathematics, which is emphasized by the National Council of Teachers of Mathematics (NCTM). This book contains 40 reproducible student activities, two investigations, a game, award certificates, and sample solutions.