Decompose a Number into Parts and Factors

One number can be rebuilt many ways — as sums of two addends or as different factor pairs giving the same product. Learners first see that the same quantity has many additive and multiplicative names, then use factor pieces to test divisibility. Flexible decomposition is the engine behind mental arithmetic and later divisibility work.

grade 2–4 NBTOA Make a Systematic ListOrganize Information in More Ways