calculator - is there a "memory save" option?

[Frankenpod]

Maybe I missed it (but the manual doesn't really say very much about this plugin).  But normally calculators with a memory function have a button "MS" for saving the currently displayed figure to memory, overwriting whatever is currently in it.  I can only see a M+ button, that adds the number to whatever is already in memory, which isn't what I wanted to do.  Am I missing something or is that feature missing from the calculator plugin?