1 1.OA.B.4 Grade 1 · Operations and Algebraic Thinking

1.OA.B.4: Subtraction is an unknown-addend problem (10 - 8: what goes with 8 to make 10?)

Understand subtraction as an unknown-addend problem.Common Core State Standards for Mathematics, as adopted in the Massachusetts Curriculum Framework for Mathematics (2017), Grade 1.

Play the game: Which Way?Steps 32, 33 of the ColorMyMath curriculum · free, no sign-up →
Steps 39–43 · Climb →Jump and Climb Stories →

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 1 standards in Operations and Algebraic Thinking

← 1.OA.B.31.OA.C.5 →

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.