To type the square root symbol, enable the Num Lock key, hold down the Alt key on your keyboard, and type the numbers 0251. If you are using a laptop computer, you must also hold down the Function key, which is not present on desktops.Continue Reading
All keyboards have a light indicating whether Num Lock is on or off. Ensure that this light is on. If not, press the Num Lock key.
The Alt key is next to the spacebar. On a laptop, the Function (Fn) key is usually in the same row.
The numeric keypad is on the far right side of a desktop keyboard. On a laptop, the keys on the right half of the keyboard also function as a numeric keypad.
While holding down the Alt key (or the Alt and Function keys on a laptop), use the numeric keypad to enter 0251.