6 is not a perfect square so its square root is irrational, therefore the decimal form can only be estimated.
√10 ≈ 3.16
The square root of 10 is a single number. That number is irrational, which means that its decimal expansion goes on forever without repeating, and cannot be expressed as a fraction.
√15 ≈ 3.17
This is not simplifiable. But this is approximately what equalled.
