2 2.OA.B.2 Grade 2 · Operations and Algebraic Thinking

2.OA.B.2: Add and subtract within 20 fluently; by the end of grade 2 know every sum of two one-digit numbers and the matching subtraction facts

Fluently add and subtract within 20 using mental strategies. By end of grade 2, know from memory all sums of two single-digit numbers and related differences.Common Core State Standards for Mathematics, as adopted in the Massachusetts Curriculum Framework for Mathematics (2017), Grade 2.

Play the game: DoublesStep 30 of the ColorMyMath curriculum · free, no sign-up →
Step 32 · Which Way? →Steps 34–38 · Jump Down →Steps 39–43 · Climb →Step 44 · Proving →Step 45 · Proving →Step 46 · Proving →Step 47 · Proving →Step 48 · Proving →

How ColorMyMath teaches it

Addition is a length — dots laid end to end on the number line. Taking away comes down the same line. Every fact is shown as a picture before it is ever asked for from memory.

Every page is free and open — nothing to install, no account, and it works on a phone or a classroom board. Every number has its own color: 1 red, 2 orange, 3 yellow, 4 green, 5 blue, 6 purple, 7 brown, 8 pink, 9 cyan, and a number is that many colored dots.

Where it sits in the curriculum

More Grade 2 standards in Operations and Algebraic Thinking

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ColorMyMath · getridoftheteacher.com · every number has its own color, and a number is that many colored dots. Matching a game to a standard is a judgement call; the official text is at doe.mass.edu.