Simple math question here, what is 1/3 of...?

well take 1 and divide it by 3 u should get .333333333 and that should be ur % so take that and times it by 253.7 that gives u 84.5666666667 then take 84.5666666667 and subtract it by the original number which is 253.7 (of course bigger number comes first) that would give u 169.1333333333 or some what number close to that if u delete every thing and plug it again to do the math