The number underneath the square root symbol

Radicand

Step-by-step explanation:

Hi, the number underneath the square root symbol is called the radicand.

In mathematics, a square root is represented with a radical symbol (√), and a number or expression underneath it that is called the radicand.

For example:

√9

In this expression the radicand is the number 9.

Feel free to ask for more if needed or if you did not understand something.