## How do calculators do arithmetic?

This article is different from others as it discusses my early experiences with microcomputer programming. The article is, however, very relevant to this Math blog because it hopes to inspire children of all ages to take a very hands-on approach to learning how calculators do arithmetic, and gives suggestions for pursuing a self-directed and very fruitful exploration into the subject. Teaching yourself how computers do arithmetic will give you a lifelong foundation for programming computers or for just understanding how computers work.

I was fortunate enough to grow up in the 1970's when microcomputers were just starting to become popular. As someone with a lifelong love of Math and an interest in computer programming I bought my first computer in the late 1970's. It was an Ohio Scientific Challenger 1P computer. It came standard with 4K of RAM. That's kilobytes, not megabytes or gigabytes. I remember plunking down a few hundred dollars to double the memory to 8K. A fun little exercise is to compare the cost of the extra 4K of memory (let's say it was $300) to the cost of 4 gigabytes of memory for a typical PC today, considering that 4GB is roughly 1 million times larger than 4KB. I say roughly, because 4GB is actually 1024^2 times larger than 4kB.