Explore Lux

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

Count on to add, back to subtract

What this lesson shows

Start at 8 on a number path and count on 3 to add 3. Start at 11 and count back 3 to take away 3.

The worked example

The lesson works this one step by step: 8 + 3 = □. Then your kid tries one like it on paper.

The steps

  1. Start at the first number
  2. Plus: count on
  3. Minus: count back
  4. Stop on the answer

Helping at home

Start at the first number. For plus, count on one number for each; for minus, count back one number for each. Draw a number path from 1 to 20 if it helps.

If your kid gets stuck

Start at the first number. Plus counts on, minus counts back.

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.5
    Relate counting to addition and subtraction (e.g., by counting on 2 to add 2).
Matches standards in 42 statesSee each state's code

More in this unit