Texas Instruments TI-73 Manual Book page 8

Pressing a number without pressing an operator (\ or T)
defaults to a positive number (+) and adds an entry to the
expression. Example: Pressing defaults to .
6 +6
You can negate a number in two ways:
• Use a to add a negative number. Example:
10 + L5 = 5
• Use T to subtract a positive number. Example:
10 N 5 = 5
When you finish entering the expression, press b. The
numerical result is displayed at the end of the expression on the
entry line, the vector history is also displayed, and the indicator is
adjusted so that it points to the result on the number line.
You can press b after a single entry or after multiple entries.
Note
Number Line/Fraction Line for the TI-73 Page 8