What is the value of 5 in this number 124.519 in a fraction?

Well, friend, the value of 5 in the number 124.519 is 5/100, because it's in the hundredths place. Every number after the decimal point represents a fraction of 10, so 5 in this case is five tenths, which simplifies to one half. Just remember, every part of a number is important and adds to the whole picture!