# UnitMath FAQ ( Options )

### How do I display my calculations extremes?

The "Show Range" option in the preferences window allows you to display all inexact results in the format minimum to best estimate to maximum.

### What fractions does UnitMath support?

With the "Show Exact Fractions" option selected in the preferences window, UnitMath will, when possible, display numbers as exact fractions. The fractions UnitMath supports are 1/2, 1/3, 1/4, 1/5, 1/6, 1/7, 1/8, 1/9, 1/10, 1/12, 1/16, 1/32, & 1/64.

### How can I make \$49.95 exact?

There are several ways to force decimal inputs to be exact.

\$12.95 pm \$0 = 12.95 \$
\$12.95 pm \$0 = 12.95 \$
\$1295/100 = 12.95 \$
\$12 + \$95/100 = 12.95 \$
( \$12.95 + \$5.90 + \$1.97 ) / 3 pm \$0 = 6.94 \$

It's often good enough to just add another decimal place. For example \$12.950 ~ ( 12.9495 to 12.95 to 12.9505 ) \$ is within 1/10 of a cent of being exact.

There is also the option "Exact Decimals" which tells UnitMath to interpret all decimals as exact.

Generally I recommend against setting exact decimals, instead use one of the above methods when you need to have a decimal interpreted as an exact number. Except for currency nearly all exact measurements are expressed as either integers or fractions of integers both of which are already considered exact by UnitMath. If you set exact decimals then all decimals will be considered exact, and you will lose the very useful information about your the precision of your data.