Count how many parts each image is divided into. The number is equal to the denominator.
Count then how many parts are colored. This number is equal to the numerator.
If you would like to have a vivid explanation with a detailed example, please read the page A fraction - Who can eat a whole cake?
Step 1: Determine the represented fractions
Count for each image how many pieces there are in total (= denominator) and how many pieces are colored (= numerator).
The following fractions are shown:
Image 1: 3/5
Image 2: 1/5
Image 3: 2/5
Step 2: Determine the solution
Which of the fractions shown corresponds to the fraction 3/5?
=> It's image number 1!