5 divided by 8 can be expressed as the fraction 5/8. This fraction represents a part of a whole, where the number 5 is the numerator (the top part of the fraction) and 8 is the denominator (the bottom part of the fraction).
To understand this better, consider that if you divide something into 8 equal parts and take 5 of those parts, you have 5/8 of the whole. This fraction is already in its simplest form, as 5 and 8 do not have any common factors other than 1.