Subtracting Reverses

This extraordinary lesson combines base ten subtraction practice with an irresistible mystery. A pattern slowly reveals itself as the class compiles data.

Story Problem – A Trip to the Bakery

This set of story problems resists easy answers, but can be cracked if students build models or draw pictures of the situation. For students who finish early, have them create their own “Trip to the Bakery” story problem.

1-2 Nim

Topics: logic, patterns, addition, counting, subtraction, divisibility and remainders (optional) Materials: Counters (tiles, beans, pennies, etc.) or paper and pencil Recommended Grades: K, 1, 2, 3, 4 Common Core: K.CC.A.2, K.CC.B.4, K.CC.B.5, K.OA.A.1, K.OA.A.2, K.OA.A.5, 1.OA.B.4, 1.OA.C.5, 2.OA.B.2, 3.OA.D.9, 3.OA.A.2, 3.OA.A.3, 4.OA.C.5, MP1, MP2, MP3, MP5, MP7, MP8 You can take one or two counters from the pile. How do …