Using Parentheses With Units In A Calculation - Texas Instruments TITANIUM TI-89 User Manual

Using Parentheses with Units in a Calculation

Using Parentheses with Units in a Calculation Using Parentheses with Units in a Calculation Using Parentheses with Units in a Calculation
In a calculation, you may need to use parentheses ( ) to group a value and its units so
that they are evaluated properly. This is particularly true for division problems. For
example:
To calculate:
100_m
---------------- -
2_s
If you have any doubt about how a value and its units will be evaluated, group
Note:
them within parentheses ( ).
Here's why you get unexpected units if you do not use parentheses. In a calculation, a
unit is treated similar to a variable. For example:
treated as . Without parentheses, the entry is calculated as:
2 _s
†
100 * _m
------------------- -
100 † _m / 2 † _s =
Constants and Measurement Units
Enter:
100_m/(2_s) 50 •
You must use parentheses
for (2_s). This is important
for division.
If you omit the parentheses,
you will get unexpected units.
For example:
100_m/2_s
† _s = 50. † _m
2
_m
------ -
_s
50. † _m † _s
is treated as
100_m
.
† _s
and is
100 † _m 2_s
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