Tutoring statistics, you see lots of great calculators. The tutor shows how to calculate one-var standard deviation on the Casio fx-991ES PLUS C.

Let’s imagine you want the standard deviation of the short list of numbers 23, -12, 0, 15, 71. Here’s how to calculate it using the Casio fx-991ES PLUS C:

1. Key in MODE then 3 then 1
2. Key 23 = -12 = 0 = 15 = 71 =
3. Perhaps surprisingly, Press AC
4. Now, Shift then 1 then 4
5. Hopefully, you see a menu offering the standard deviation, mean, and so on. Choose the one you want, then press Enter.

Source:

Casio fx-991ES PLUS C User’s Guide.

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.