Instructions

1

Calculate a tip on your restaurant bill. Suppose your bill happens to be $64.35 and you would like to leave a 15 percent tip. Type the following into your calculator: 64.35 * 15 %

Answer: 9.6525 or $9.65 after rounding.

Most simple calculators will give an answer right here without having to press the = sign. If yours does not, press = and see if you get the right answer. Alternatively, you can calculate this percentage by typing in 64.35 15 / 100 or 64.35 0.15 (All that the percent key did here was division by a hundred.)
2

Calculate a sale price. If you bought shoes that originally cost $139, but are now discounted by 35 percent, type the following in your calculator: 139 - 35 % =

Answer: 90.35 or $90.35

This calculation is amazingly easy with the percent key. Alternatively, you would first have to calculate what 35 percent of $139 is and then subtract that answer from 139:

139 * 35 / 100 = 48.65

139 - 48.65 = 90.35
3

Calculate multiple discounts on an item and add the sales tax. Suppose those shoes from the previous step went on clearance for an additional 40 percent off -- so 35 percent off, 40 percent off on top of that and then an additional 5 percent sales tax. Again, it's easy with the percent key: 139 - 35 % - 40 % + 5 % =

Answer: 56.9205 or $56.92 after rounding.

So you can add or subtract any increases or decreases in percentages using the percent key. It gets a bit more involved to do this without the percent key, however. You would have to do it the same way as in Step 4 for each subsequent percentage increase or decrease.