In the comparison of numbers, we start from the left digit and moves towards the right.
Given the numbers 5.099 and 5.1
The unit digit of both numbers is 5.
The tenth digit of 5.099 is 0
The tenth digit of 5.1 is 1.
Since 1 > 0, we conclude that 5.1 is larger than 5.099.
The digits .099 are after the decimal point and the rule of having more digits does not count in this case.