If you’ve ever used a computer, you’ve probably seen it: a grid of numbers and math operators on the far right of the keyboard. It’s a number pad, but how did it get there and why is it designed that way? Let’s explore its origins.
It’s all about the math
Computers have numeric keypads because they make repetitive data entry easy. They allow you to type numbers and perform math operations quickly, with just one hand. The modern design of numeric keypads may seem obvious today, but it is the product of decades of refinement in adding machine technology, most of which took place more than 100 years ago.
The modern numeric keypad layout, sometimes called the “ten-key” layout, traces its origins to David Sundstrand, whose company released the first commercial ten-key mechanical adding machine in 1914. Before the ten-key layout, the Most adding machines used a complex layout that included more than 90 keys, with buttons for numbers 0 through 9 in nine columns. (In fact, many companies continued to use this more complex design for decades due to patent restrictions.)
In Sundstrand’s much simpler adding machine key layout, you can see the rudiments of the now-standard configuration: ten number keys, arranged in three rows of three with the “0” key below them. The numbers count up from 1 to 9 starting at the bottom left corner of the grid.
Compare this layout to a phone keypad, which features the “1” key in the upper left corner of the number grid. The design of the telephone has its origins in a usability study conducted in 1960 by Bell Labs to determine the most efficient design for telephone devices with touch-tone buttons.
Sundstrand’s company patented the “tenkey” adding machine design in 1914 and advertised the design as an easier and faster alternative to competing keyboards. After the patent expired, Sundstrand’s ten-key design was imitated by many companies. By the 1950s, tenkey had become a common key design for adding machines on the market.
As electronic adding machines replaced mechanical ones in the 1960s, the tenkey design carried on. Generations of clerks learned to operate tenkey machines for accounting and, later, for data entry on early tabulating machines. So when it came to data entry on computers, it was natural to go with the standard ten-key layout.
Numeric keypads at the beginning of computers
To find the origins of number pads on computer keyboards, you have to go back to the dawn of the digital computer itself. As early as 1951, the operator’s console of the UNIVAC I, one of the first commercial digital computers, included a numeric keypad on its keyboard.
When the personal computer revolution arrived in the mid-1970s, numeric keypads arrived. Some early PCs, including the Sol-20, the CompuColor 8001 (both 1976), and the Commodore PET (1977) included ten-key style numeric keypads on their keyboards. In general, the more business-oriented the computer, the more likely it is to include a numeric keypad to help with data entry tasks.
When IBM released its own personal computer in 1981, it also included a numeric keypad on its keyboard in the ten-key layout. IBM also included math operator keys and a Num Lock key, which toggled functions between numeric keypad mode and using some of the keyboard keys as cursor (arrow) keys.
From PC to everywhere
In 1984, IBM introduced its extended 101-key keyboard, now better known as the “Model M,” and of course the number pad wasn’t left out.
This new 101-key keyboard layout soon became an industry standard among compatible PCs (eventually making its way to the Mac in the form of the Apple Extended Keyboard). As manufacturers copied IBM’s design, the number pad became a standard item on many PCs of the 1980s, ’90s, and 2000s.
RELATED: Why am I still using a 34 year old IBM Model M keyboard
Interestingly, while you usually find number pads on the right side of a keyboard, not all computers set them up that way. The 1989 Macintosh Portable included a reconfigurable keyboard that allowed you to place a number pad on the left or right side of the keyboard, making it a rare exception to the rule.
And some computers don’t include numeric keypads at all, but still allow you to simulate them. For example, many laptops let you press a Num Lock key and turn a grid of letter keys into a number pad for quick data entry on the go.
Of course, if your laptop or keyboard doesn’t include a built-in keyboard, you can purchase a separate keyboard that connects via USB. These stand-alone numeric keypads also have a proud tradition in personal computers, going back at least as far as the Atari 800 in 1979.
With so many people out there entering data into spreadsheets, programming, and otherwise, number pads are likely to stay with us as long as we have computer keyboards. Mathematics will never become obsolete.