Why are square roots called square roots? Well to start off, square roots is the factor that equals that number when it is times itself. So take 25 as an example. 5 would be its square root because 5 times 5 equals 25. I think square roots are called square roots because I think of it as a square; squares all have equal sides. If all sides of the square are the same, it would be the square root. I'm not sure if this definition is correct, but I think this is what it would most likely be similar too. Another name that could replace square roots is perfect squares. Perfect squares are when the square root is not a decimal or fraction. For example, 4, 16, 25, 49, etc are perfect squares because their square roots are perfect; they aren't decimals or fractions.