The difference you're seeing is due to the way Excel calculates a
number compared to the way it displays a number. If you divide 100 / 3
on a calculator, you get 33.3333333 with infinitely recurring threes.
If Excel performs this calculation in a cell formatted for currency,
the answer will display as $33.33. The recurring threes are still
there, but they are not displayed.

Check out the ROUND() function, which allows you to control the number
of decimal places. In this example, =ROUND(100/3,2) the answer is
33.33 with no further recurring threes.