How to add a list of numbers
*Add as usual
*find compliments (numbers that add up to ten)
Example:
9 ١
2 ٢
3 ٢
5 ٢
1 ١
__+
20
Everyone will agree that instead of adding from top to bottom it is faster to look for numbers that add up to ten. 9 & 1 is 10 and so is 5+2 & 3
2 ٣
9 ١
4 ٢
3 ٣
6 ٢
5 ٣
1 ١
_____+
30
Checking off compliments mentally with Eastern Arabic numerals or Hebrew letters may be useful
