Givens
Male = 138,053,563
Female = 143,368,343
Total
The total equals 281 421 906
Percents
Male = (138,053,563 / 281 421 906) * 100 = 49.1%
Female = ( 143,368,343/ 281 421 906) * 100 = 50.94%
Rounded
Male = 49
Female = 51
Comment.
To find this %s you could just use the first 3 digits of everything.
Total = 138 + 143 = 281
% male = (138/281) = 49.1
% female = (143/281) * 100 = 50.88
These give you the same answers when rounding.