What this lesson shows
12 − □ = 5 asks 5 + □ = 12. The box is 7.
The worked example
The lesson works this one step by step: 12 − □ = 5. Then your kid tries one like it on paper.
The steps
- The first number is the whole
- The answer side is the part left
- Part left plus the box makes the whole
- Check by subtracting
Helping at home
The first number is the whole, and the number after the equal sign is the part left. Ask: the part left plus what makes the whole? Then check by subtracting.
If your kid gets stuck
The part left plus what makes the whole?
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.