Learning to use a 10-key calculator is indispensable in many business environments. The name is a misnomer, as there are more than ten keys, but it’s a basic calculator with few functions beyond adding, subtracting, division and multiplication.

What Is a Ten-Key Adding Machine?

A ten-key adding machine has the numbers zero through nine, then function keys for addition, multiplication, division and subtraction. There’s a total button (often shown as an equal sign), a decimal button, a display screen, a memory key and a clear-all key.

In the absence of a proper 10-key calculator, many people now use the number pad on a computer keyboard, which offers many of the same basic functions and layout of the main keys – the math functions, numbers, decimal and enter in place of the equal sign – but the display is instead on your computer screen, rather than the keypad.

What Is the 10-Key Experience?

With 10-key skills, you touch-type to input data while looking at your source material for the data. This means being fast and efficient. If time is money, then a ten-key machine adds dollars to your day.

Accountants are 10-key whizzes and using these machines make their job much easier. Having a 10-key calculator that can print off the working figures you’ve been inputting can allow you to easily double-check work after all the inputting is complete. You can go through the printed figures to see if you’ve caught everything. Many users of the 10-key calculators will then affix the printed equations to the pertinent stack of receipts or invoices as proof of work. Even if you are your own boss, it can be great to put this kind of paper-trail oversight to work.

To use the printing feature on a standalone calculator, refer to your specific machine's user's manual for instructions.

How to Operate a 10-key Calculator

There are great practical training programs available on the internet, but the gist of these is that the index, middle, and ring finger do most of the work on a 10-key number pad.

The middle finger gets positioned on the five and the index over the four, and the ring over the three. Each works the numbers above and below that row, too. Using the thumb and pinky fingers on the zero and equals/functions keys help. It can be challenging for those with not-so-graceful outer digits, but you'll develop the dexterity in your little finger and thumb, and it will speed things up tremendously over time.

Most number pads and 10-key calculators feature a tiny raised bump or nodule on the "five" key. This is so you can become an expert touch-typist with the calculator. Think of this as a Braille guide to the middle finger’s home position.

When entering data, you should be able to do it without looking. Use the bump on the five to keep yourself centered. One key above it is eight, below it is the two. Above the six is the nine and below it is three, both the domain of your ring finger. Your index finger goes one up for the seven and down for the one, while its home key is the four.

Practice Makes Perfect

Like typing and piano and any other manual dexterity task, it’s in practice that you’ll find perfection. Getting started with a 10-key adding machine may feel awkward and bump-in-the-night at first, but don’t look at the keypad. Look at your source material and try hard to type without checking finger positions. You’ll get the hang of it faster than you think, and your future accounting, bookkeeping, auditing and other numerical data work will be a breeze.

These days, there’s no real need to get a separate 10-key adding machine, but the printing feature is a valuable thing to have. If you want to avoid the expenditure, then there’s a number pad on most full-size keyboards. But if you work primarily on a laptop, you can order a USB-powered number pad to plug in for portable work. In fact, there's even a Bluetooth-powered 10-key pad to use with smartphones if you need truly portable processing.

In all cases, the layout for numbers is the same as on an old-school 10-key adding machine, and all the same skills apply. Now, with a little practice and some patience, you’ll find you’ve got all the 10-key skills you could possibly need.