3 divided by 5 can be expressed as a fraction by simply writing it as 3/5. This shows that 3 is the numerator (the top part of the fraction) and 5 is the denominator (the bottom part of the fraction).
In this case, the numerator represents how many parts we have (which is 3), and the denominator represents how many total parts we are dividing into (which is 5). So, 3/5 indicates that we have three out of the five equal parts.