The French :)(just had a little quiz with this question in it and i got a hundred percent :P)
Move the decimal point 4 digits to the left. Note that the decimal point may be implied: 456 is the same as 456.0, so you can imagine a decimal point after the "456", even though it is not written...
Four can always divide into the last two digits of a number divisible by 4.
If you mean "divide and conquer", that saying was used by Caesar and Napoleon afaik.
Is the sum of the digits a multiple of 9?