What this lesson shows
45 + □ = 23 + 46. The right side is 69, so the box is 24.
The worked example
The lesson works this one step by step: 45 + □ = 23 + 46. Then your kid tries one like it on paper.
The steps
- Work out the side with no box
- The box side makes the same
- Subtract to find the box
- Check by adding
Helping at home
Work out the side with no box first. The side with the box must make the same number. Subtract to find the box, then check by adding.
If your kid gets stuck
Start with the side with no box.
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.