A natural number m is called a perfect square number if it can be expressed as where n is also a natural number. For example, 4 is a perfect square number because it is a natural number and it can be expressed as and 2 is also a natural number.
If you want to recall what are perfect square numbers then please refer to my article on What are the perfect square numbers. This article asks a question that how many natural numbers lie between two consecutive perfect square numbers. You can also ask the same question as how many non-perfect square numbers lie between two consecutive perfect square numbers? Can we come up with a general formula for that?