The tiles · Kindergarten to grade 2
Odometer
Place value as wheels that roll over
On the way This tile's page is up; the playable version follows.
What your child does
A stack of wheels, 0 to 9 on each. Rolling a wheel past 9 bumps the next one. Your child turns the wheels to count on, to add ten, to add a hundred, and feels the ripple when a nine rolls over.
This is where the carry is felt one number at a time, before any column method: why 9 and one more rolls, why 199 and one more rolls two places, and what a zero in the middle of a number means.
What it teaches
- One more, one less
- Counting on from any number
- Ten more, ten less
- Ten or a hundred more and less
- Crossing hundreds when counting up
- Three-digit subtraction
Mistakes it recognises as your child plays
- Ten more changes the ones digit
- Adding ten without the carry into hundreds
- Stopping the count at the ten
- Borrowing upwards when counting past a ten
- Borrowing without taking one from the next column
See what it finds.
Odometer is also one of the games in the five-minute subtraction with regrouping (borrowing) check, which plays several tiles, picks the next problem from the last answer, and names the pattern it sees.
The other tiles
Stacks · Carry · Make Ten · Chart · Time · Fraction · Brick · Rectangle
Cardinal Math watches for all of these, every day.
Inside the app the same patterns are caught as your child plays, across the whole of K to grade 5, and explained to you in plain words. One price, no ads, no streaks. Coming to iPhone and iPad.
Tell me when it's out