Something like 4//1/255 ?
just multiply The number you started with be the denominator of the fraction.
4 * 255 = 1020
The reason why is that though I didn't say so you are actually multiply both top and bottom by 255
4 * 255
==
1 * 255
--
255
The bottom 255s cancel. and you are left with 4 * 255 on the top.
Short cut you want. Short cut you get.
Thanks for posting.