5 ms·
They keep adding to nine. 137×9 = 1233 . 34457×9=310113. When it breaks down: 99x9=891 sums to 18, sums to 9.
by jmlundberg 6y ago
They keep adding to nine. 137×9 = 1233 . 34457×9=310113. When it breaks down: 99x9=891 sums to 18, sums to 9.
- jjk166 6y ago99 on its own is also an example where it breaks down, which is why I stopped at 10, but yes all multiples of 9 in base 10 have digits summing to a multiple of 9.