When Dave Kunz entered the workforce in 1972, he used a manual adding machine.

"It was like a slot machine. It made a lot of noise and had a lot of moving parts," says Kunz, professor of finance at Southeast Missouri State University's Harrison College of Business.

It wasn't until a year after he started working that he got a digital calculator. "And all it could do was add, subtract, multiply and divide," he says. "It cost about $300, really leading-edge stuff."

Kunz uses his experience in the private sector to illustrate to his students how business has changed as technology has evolved.

Another example: "We've eliminated a lot of the middle administrative support," he says. "People work at desks and are expert at keyboarding. Better than me, anyway. I spent 20 years with a secretary."

Of course, computers are one of the most recognizable technological advances of the last 50 years or so.

Kunz says when he started in the private sector, he had access to computers, but not the PCs many of us are familiar with today -- these were mainframe computers that did batch processing, an execution of a series of programs without manual intervention.

"Computers were great for things you did a lot of, frequently, that didn't change much," he says. "(They) didn't handle exceptions well at all."

Another difference: Those computers didn't process real-time data. "If you wanted to find an inventory level, you didn't have a way to do that," Kunz says. "You could look at the report from last night or last week, but until the new information was entered manually, you didn't have an updated inventory."

Now, he says, stores are able to track inventory instantaneously. For example, when the cashier swipes your purchases at the grocery store, it's not just ringing in the price, but also updating the store's inventory database.

Technology also makes the marketplace more efficient and speeds the increase in business, he says. "If you're shopping for a car, you don't have to rely on a couple of manuals and the dealership for information. You can go online and get the information from a variety of sources."

As for the speed of business, Kunz cites his experience doing contract reviews. "We would put (the contract) in the mail, then they would review and sent it back," he says. "With the mail, it was three or four days. Now it's instantaneous: You can attach the contract in an email and it's right back to you. There's not as much time to think about things."

Technology has also made doing business easier in some ways. Instead of the mechanical adding machine Kunz started with, electronic spreadsheets can process data automatically. "When I was in financial planning doing budgets, we were doing manually. You could change something, but you'd have to go back and change other things," he says. "With the advent of spreadsheets, you can do what-if (scenarios) instantly."

So with all the technological advances in the past 50 or 60 years, what has had the most pivotal effect on business?

"I'd have to say the advent and utilization of the Internet," Kunz says. "But we couldn't have the Internet without PCs. The fact that now everyone has a personal computer at their desk, laptops, iPads, phones that act as a computer: You can take data and adjust it and review it in lots of easier ways."

Did you know ...

The forerunner of the typewriters we'd recognize today was invented by Latham Sholes, Carlos Glidden and Samuel Soule between 1867 and 1873. Their final design could operate faster than a man could write with a pen and all the letters were legible. The three contacted the E. Remington & Sons company, manufacturers of firearms and sewing machines, to build and sell the "Type-Writer." The invention was a hit in the business world. By 1909, 89 separate typewriter manufacturers existed in the United States alone.

Source: IBM archives