fractions are also known as rational numbers (they can be written as repeating decimals or decimals that have an ending) pi is not rational cause it never ends
a subset (smaller set) of rational numbers are the integers (positive and negative whole numbers)
a subset of the integers are whole numbers which begin with 0 and go up by 1's
As a Venn diagram it would be 1 big circle titled fractions (or rationals), a smaller circle completely inside the big one titled Integers and then a 3rd circle inside the 2nd titled whole numbers.