45! An easy way to find if a number is divisible by 3 is to add the numbers.
For example, 45 is divisible because 4+5 = 9 and you know that 3 goes into 9.
467 is not because 4+6+7= 17 and 3 doesn't go into 17.
230 is not because 2+3+0=5 and 3 doesn't go into 5.
91 is not because 9+1=10 and 3 doesn't go into 10.
