Stage 2 · The Four Operations & Estimation
2.1.3 Addition and Subtraction Are a Matched Pair
2.1 Addition & Subtraction: Putting Together and Taking Away
Point 3 of 6
2.1.3 Addition and Subtraction Are a Matched Pair
Core ideaAdd some and then take it back and you land right where you started, so 5 + 3 = 8 and 8 − 3 = 5 undo each other.
Module goal. Move from counting to operating, building the real-world meaning of addition and subtraction, their inverse relationship, and column arithmetic for multi-digit numbers.