What is an open number line?
An open number line is a blank line your kid draws to add or subtract by making "jumps". Instead of stacking numbers, they hop from one number to the next in friendly chunks, like jumping to the next ten.
Start at 38
Tap a button, or tap any spot on the line to jump there.
How you probably learned it
To add 38 + 25 you stacked the numbers, added 8 + 5 = 13, wrote the 3, and carried the 1.
How your kid is learning it
Your kid starts at 38 and jumps: +2 to get to 40, then +20 to 60, then +3 to 63. Each jump is easy to do in your head, and they can see why the answer is right.
Why "open"?
The line has no tick marks for every number. Kids only write the numbers they land on, so the line can stretch to any size, from 8 + 5 to 386 + 247.
It works for subtraction too
For 52 − 17, kids can count up from 17 to 52: +3 to 20, +30 to 50, +2 to 52. The jumps add up to 35, so 52 − 17 = 35. Many kids find this easier than borrowing.
