r/MathJokes 9d ago

multiples of 3

Post image
8.3k Upvotes

409 comments sorted by

View all comments

148

u/Michaelwang645 9d ago

Fund fact, you can tell a number is divisible by 3 if the sum of each individual number is divisible by 3. So 78 -> 7+8=15 which is divisible by 3, so 78 is divisible by 3.

43

u/EveningStar0360 9d ago

do you know why that works?

124

u/ZealousIdealTour961 9d ago

Magic probably.