HOW DO YOU SAVE A NUMBER IN MEMORY ON A ti-30xa?

SOURCE: how to clear the memory key on Texas instrument

Hello,
Your calculator has 3 memories (M1, M2,M3)
To store the number 170 in M1 use 170[STO]1
To recall a number from M1 use [RCL]1
To add a number to the content of M1 [2nd][SUM]1 (adds displayed value to contents of M1).
[2nd][EXC] 2 exchanges the value already displayed with the contents of M2:

To erase (clear) a memory register, just store 0 in it.

Hope it helps.

SOURCE: Books on TI-30Xa

Hello,
Honestly, you do not need any additional books to learn how to use it.
You can however design your own small programs to do certain calculations that require more than one step; Exemple: calculate the area of a cylinder knowing its height and radius. or the volume. you will have to use the memories to store the data and the internediate results.
Concentrate on learning how to use it efficiently on your exams.
Hope it helps