Memory / tending to zero

In 1971 I started studying for maths A level. I was at a comprehensive school but they weren't bog-standard back then, nor were they abbreviated to 'comps'. They were still fairly unusual and it was also unusual to find pupils in a comprehensive school who might be interested in going on to university. But the school was keen to show that it was as good as anywhere else so, in the age of log tables and slide rules, the maths department bought four calculators for our A-level class to share. They cost £50 each (that's about £700 each now) and they had just the four basic functions: add, subtract, multiply and divide. No whizzy reciprocals or square roots - we still had to go back to our log books for those.

Thirty years later this little thing came onto the market. More powerful, smaller, lighter and solar-powered. It didn't cost anything like £50 but it cost quite a bit more than the zero that it's worth now that anyone who wants to calculate anything can do it on their phone.

So this piece of history is headed for the dump.