Mental adding and subtracting with jumps
Show each addition and subtraction as jumps on a number line: tens then ones, or to the next ten first.
- UK: Year 2
- France: grade 1
- Germany: grade 1
- Iran: grade 1
- Afghanistan: grade 1
- Syria: grade 1
- Ukraine: grade 1
- Russia: grade 2
Guide
On a number line, addition is a jump to the right and subtraction is a jump to the left.
The arcs show the jumps. You tap where each jump lands; the number on the arc says how far you jumped, and the number under the point says where you landed.
For two-digit numbers, split the second number: for 37 + 25, jump 20 (to 57) and then 5 (to 62). Sometimes it's easier to jump to the next ten first: for 8 + 5, jump 2 to 10, then 3 more.
In class you may draw an empty number line with just the numbers you need. This one has marks so you can check each jump.
You can drag a point, or tap it and move it with the arrow keys. "Clear points" starts again.