#color(white)()#
#color(white)(00000)204#
#color(white)(0000)"/"color(white)(000)"\"#
#color(white)(000)2color(white)(0000)102#
#color(white)(0000000)"/"color(white)(000)"\"#
#color(white)(000000)2color(white)(0000)51#
#color(white)(0000000000)"/"color(white)(00)"\"#
#color(white)(000000000)3color(white)(000)17#
- #204# ends with an even digit, so we can tell that it's divisible by #2#...
#204 = 2 xx 102#
#color(white)()#
* #102# ends with an even digit, so we can tell that it's divisible by #2#...
#102 = 2 xx 51#
#color(white)()#
* #51# ends in an odd digit, so is not divisible by #2#, but the sum of its digits is #5+1 = 6#, which is divisible by #3#. So we can tell that #51# is divisible by #3#...
#51 = 3 xx 17#
#color(white)()#
* #17# is a prime number, so stop.
