Torez has 4 apples, Martin takes quarter of them and gives Torez one back. How many apples does Torez have after that?

Hello!

First, let's find how much apples is a quarter (one-fourth) of apples.

It is evident that    i.e. is the sum of equal parts, each of them is one. So by the definition of a one-fourth part a quarter of is

Second, Martin takes quarter of apples, i.e. apple. The remaining quantity after this is Then he gives one apple back, so the quantity becomes .

And this is the answer: after these manipulations Torez has 4 apples again.