While there were various electronic calculators on the market in the early 1970s, they were all fairly expensive and a little too large to be called "pocket" calculators. The first one to hit the big time was from Texas Instruments, the SR-10, in around 1973. It sold for about $150. It was advertised heavily on TV and in various magazines. I had a friend who bought one and I thought it was really neat, but $150 was beyond my budget limits at the time. A little later, maybe 1974, I did buy a calculator, but it wasn't a TI (Japanese as remember) and it was too big to fit into a pocket. I had a friend who worked at K-Mart, and he bought one for me at his employee discount price. It was less than $100, but I don't remember the exact price. It would do only the basic four functions, but maybe it also had square and square root buttons. One nice thing about it was that the display had large glowing green numbers so you didn't have to squint. I used it a lot. It finally died on me. Compare that to today. You can go to Dollar Tree and buy a full featured scientific calculator for a dollar. And it works well. I have one.