About this game

Addition and subtraction go together

Addition and subtraction go together: a free Grade 1 math game for ages 6-7. Each round draws 7 questions; instructions are read aloud and every answer is checked and explained.

How it plays and why it helps

Many children treat subtraction as a separate, harder world. Addition and subtraction go together says the opposite on every card: work out 7 − 3 by using the addition you already know. Six cards subtract, from 7 − 3 to 19 − 12, and two add, 10 + 6 and 9 + 9. Seven of the eight cards make a round in this Grade 1 game; each is read aloud, your child taps one of four numbers, and every answer is checked.

Behind every card sits the inverse relationship: if 3 + 4 = 7, then 7 − 3 = 4. A fact family lets one known fact answer three questions, which makes subtraction feel like addition read backward. The hint keeps the idea in view: addition and subtraction can check each other.

On most subtraction cards, one choice is the sum instead: 10 for 7 − 3, 12 for 7 − 5, 31 for 19 − 12. A child who sees two numbers and adds them lands right on it. That is no accident. Point to the minus sign and ask, "Are we putting together or taking apart?" Praise the check: "You tested your answer with an addition."

Aligned with

  • 1.OA.B.4 Understand subtraction as an unknown-addend problem. For example, subtract 10 - 8 by finding the number that makes 10 when added to 8.
  • 1.OA.D.8 Determine the unknown whole number in an addition or subtraction equation relating three whole numbers. For example, determine the unknown number that makes the equation true in each of the equations 8 + ? = 11, 5 = _ - 3, 6 + 6 = _.
  • 1.OA.A.1 Use addition and subtraction within 20 to solve word problems involving situations of adding to, taking from, putting together, taking apart, and comparing, with unknowns in all positions, e.g., by using objects, drawings, and equations with a symbol for the unknown number to represent the problem.

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