Sonny, I remember when you had to add and subtract and multiply. And they made you do it right there in front of the questioner, in your young empty head. Occasionally they'd take pity on you and allow a pencil and paper. The real wild and crazy guys that could work a slide rule would always get A's, not girls. And then they came.
Calculators. Oh man, indoor plumbing has nothing on them. I remember paying close to a week's pay for a calculator that would do sine and cosine and tangent calculations and a few other things I've forgotten and never needed again. Now they give you stuff with ten thousand times the computing power with your Happy Meal.
Vintage Technology keeps an on-line museum of these bad boys, and it's wonderful reading for the nostalgic, and the young and curious as well. Aww, man, I had a Texas Instruments TI-30:
It's like looking at baby pictures of old friends. Click on each one and you can drill down through all the models and specs. A real timewaster, so make sure you're at work. Research, boss, research.