What is between 5.1 and 5.2 in math?

In mathematics, the numbers between 5.1 and 5.2 are any decimal numbers that lie within that range. For example, 5.15, 5.12, and 5.19 are all valid numbers between 5.1 and 5.2. Essentially, any number greater than 5.1 and less than 5.2 qualifies, including infinitely many decimals.