Having Fun with Percents and the Ten-Key

Percentages are unique in that there are multiple ways to perform calculations with them. I'll share two methods. The quick way, and the other way.

The other way

Let's start with the slow, long, you're-wasting-my-time method of adding a percentage of a number to same number.

We want to calculate 30,000 + 6% (of 30,000).

[ 30,000 ] [ x ] [ .06 ] [ = ] [ + ] [ 30,000 ] [ + ] [ * or T ]

Practical applications of this include sales tax and pay raises.

At 31,800, someone got a nice little raise.

The quick way—or the way to a calculator's heart

  1. Press: [ C/CE (or C) ] [ C/CE (or C) ]
  2. Press: [ 30000 ] [ x ] [ 6 ] [ % ] [ + ]
    See your total there on the screen now? I hope it shows 31,800. If it doesn't, start over at #1 above.
  3. Press: [ + ] [ * (or T) ]
    If you forgot that extra addition key, I'm sure you noticed that your lovely 31,800 just flatlined it back to zero. If you didn't, congratulations! You can now add additional numbers to that or just clear it out and move on. Either way, you've accomplished something here and learned that there's a shortcut to lovely percents that takes all the hassle right out of 'em.

Aren't percentages grand?

Find out how to use the tax rate function of printing calculators next!

Favorite Printing Calculator

Recommended Printing Ten Key Calculator

The SHARP EL-1801PIII is actually sitting on my desk at this very moment. I haven't used a better printing calculator. In fact, I have two of these babies (if you drop the little III at the end). One at the office (1801P) and one in my home office (1801PIII).


Read a short history of adding machines at Wikipedia®

A ten-key calculator is better

...when you need to add or subtract long columns of numbers

...for doing your checkbook

...if you want to add or subtract sales tax from something

...on Fridays

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