Can you split 64 into two parts so that if each of the two parts is divided by 4 and the two quotients are added, their sum will be one-fourth of the original 64?
You can? Is it, uh, easy? Why? Do some algebra to show why.
The two parts can be represented by x and 64 – x. Then x/4 + (64 – x)/4 = 64/4, so no matter how you split up 64, if you divide each part by 4 and add the quotients, you will always get 1/4 of 64, or 16.