Section 1: General Operations25
×   
  12.00
  Reverses division operation: you are back where you started.
gLSTX   
  3.00
  Retrieves last number displayed before multiplication operation.
÷   
  9.00
  Correct operation produces desired results.
If you want to correct a number in a long calculation, Last X can save you from starting over. For example, divide 12 by 2.157 after you have divided by 3.157 by mistake.
12 ENTER  3.147 ÷  
  3.80
  You wanted to divide by 2.157, not 3,157.
gLSTX   
  3.16
  Retrieves last number displayed preceding operation.
×   
  12.00
  You’re back at the beginning.
2.157 ×  
  5.56
  Correct operation produces desired results.
Another, and possibly more important, use for Last X is in functions where x appears more than once. Without going into details since we have not yet discussed functions, examples might be:
  sin x  , yx — √x, sin x + cos3 x
 
  x
In each case x is saved in Last X after the first operation is performed.
The following operations (including inverses) save x in Last X:
+, , ×, ÷,  D.MS, D.MS+, INT, LN, LOG,  OCT, R P, SIN, COS, TAN, n!,  , 1/x, yX, ABS.
Note that CLx does not affect the Last X register.