Explore Lux

1st grade math · Unit 2: Equations and three numbers

Find the ten first

What this lesson shows

8 + 7 + 2: add 8 + 2 to make 10, then 7 more is 17.

The worked example

The lesson works this one step by step: 8 + 7 + 2. Then your kid tries one like it on paper.

The steps

  1. Find two that make 10
  2. Add them first
  3. 10 plus the rest

Helping at home

Look for two numbers that make 10 and circle them. Add those first, then add the last number to 10.

If your kid gets stuck

Which two make 10?

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.B.3
    Apply properties of operations as strategies to add and subtract. Examples: If 8 + 3 = 11 is known, then 3 + 8 = 11 is also known. (Commutative property of addition.) To add 2 + 6 + 4, the second two numbers can be added to make a ten, so 2 + 6 + 4 = 2 + 10 = 12. (Associative property of addition.)
Matches standards in 48 statesSee each state's code

More in this unit