+STO

Add the previous number to the number stored at the address given at the top of the stack. Although it is easy to determine the address associated with a given variable, and hence use that address directly, it is advisable always to use a variable name to load an address into the stack before using +STO.

Example:

 0.0
COD> VAR TMP 5 TMP STO TMP RCL
 0.0 5.0
COD> TMP +STO
 0.0
COD> TMP RCL
 0.0 10.0