Hold down the shift key (Alt key) with your left hand, then press 4 1420 in turn, and release your left hand, and "√" will appear.

Similarly:

Press 4 1469 is ↓

Press 4 1466 Yes →

Press 4 1467 Yes.

Press 4308 1 Yes.

Press 43082 Yes.

Press 43083 Yes.

Press 43084 Yes.

Press 43 125 Yes.

Press 43 126 Yes.

Press 43 127 Yes.

Pressing 178 is a square symbol (2)

Pressing 179 is a cubic symbol (3).

Press 179 to type (3), and then press 4 1420 to type the cube root 3√.

Press 4 1455 yes ★

Press 4 146 1 Yes □

Press 4 1462 Yes.

Press 4 1439 Yes.

Press 4 1440. Yes

Press 4 1423 Yes.

According to 4 1463 is delta.

Press 4 1430 is ≈.

Press 4 1420 is the root sign √.

Pressing 4 1429 is an equal sign.

Press 4 142 1 to be a vertical sign?.

Press 4 1465 Yes. ※。