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1st grade math · Unit 1: Adding and subtracting within 20

Ways to make 10

What this lesson shows

Ten counters in two colors: 9 + 1, 8 + 2, 7 + 3, every pair that makes 10.

The worked example

The lesson works this one step by step: 7 + □ = 10. Then your kid tries one like it on paper.

The steps

  1. Fill a ten frame
  2. Count the empty squares
  3. The two parts make 10

Helping at home

Put the number you know in a ten frame and count the empty squares. That is the other part of 10. Say the pairs out loud until they come quickly.

If your kid gets stuck

How many empty squares?

Watch it with Lux

With Lux, this lesson is a narrated video and a printed page your kid works on. Then Lux helps with the same math on their own worksheet, one question at a time.

See how Lux works

Standards

  • Common Core 1.OA.C.6
    Add and subtract within 20, demonstrating fluency for addition and subtraction within 10. Use strategies such as counting on; making ten (e.g., 8 + 6 = 8 + 2 + 4 = 10 + 4 = 14); decomposing a number leading to a ten (e.g., 13 - 4 = 13 - 3 - 1 = 10 - 1 = 9); using the relationship between addition and subtraction (e.g., knowing that 8 + 4 = 12, one knows 12 - 8 = 4); and creating equivalent but easier or known sums (e.g., adding 6 + 7 by creating the known equivalent 6 + 6 + 1 = 12 + 1 = 13).
Matches standards in 49 statesSee each state's code

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