The number 8 is a whole number. When expressed as a decimal, it is simply represented as 8.0. In the decimal system, every whole number can be represented with a decimal point followed by zeros. Thus, 8.0 shows that there are no fractional parts of the number.
Decimals help in clearly expressing whole numbers and their fractional counterparts. In this case, since 8 is a whole number, adding a decimal point and a zero does not change its value, but it does emphasize that it can also be considered in the context of decimal notation.