Which is greater of two positive numbers?

It's the number that has more digits to the left of the decimal point (if there is no decimal point, it's the number with more digits).

If the number of digits to the left of the decimal point is the same, find the position farthest to the left where the digits are different. The number with the greater of those two digits is the greater number.

For example, 10000 is greater than 9999 because 10000 has more digits, and 6350 is greater than 6349 because the farthest-left position that is different is the tens place, and 5 is greater than 4.