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Some additions: 3's multiples' digits always add up to a multiple of three. So 69 is 6+9 which is 18, a multiple of three. 9's multiples' digits always add up
by kendallpark 11y ago
Some additions:
3's multiples' digits always add up to a multiple of three. So 69 is 6+9 which is 18, a multiple of three.
9's multiples' digits always add up to a multiple of nine. So 108 is 1+0+8 which is 9, a multiple of 9.
6's multiples' digits are always even and add up to a multiple of three.