This is not binary math, it's hexadecimal math ;-) This means that we use 16 "digits". Instead of counting from 0 to 9, we count from 0 to 15, using letters for digits greater than 9.
So: A = 10, B = 11, C = 12, D = 13, E = 14, F = 15
Going from right to left, multiply the second digit by 16, the third by 256 (16 * 16), the fourth by 4096 (16 * 16 * 16) and so on...
So for example:
$ABCD = ($A * 4096) + ($B * 256) + ($C * 16) + $D = (10 * 4096) + (11 * 256) + (12 * 16) + 13 = 43981
Well, at least I can understand myself ;-). Hope this helps. Or you can google for "hex maths" ;-)
So: A = 10, B = 11, C = 12, D = 13, E = 14, F = 15
Going from right to left, multiply the second digit by 16, the third by 256 (16 * 16), the fourth by 4096 (16 * 16 * 16) and so on...
So for example:
$ABCD = ($A * 4096) + ($B * 256) + ($C * 16) + $D = (10 * 4096) + (11 * 256) + (12 * 16) + 13 = 43981
Well, at least I can understand myself ;-). Hope this helps. Or you can google for "hex maths" ;-)