Technology...

....is the theme for today's Mono Monday hosted by Skeena.  In the 17th century the slide rule, an example of educational technology, was developed by Rev. William Oughtred.  The slide rule was used as a calculation tool in science and engineer and remained in use until the early 1970s when they were effectively replaced by the handheld scientific calculator, in fact the early models were known as slide-rule calculators. This Tandy, previously known as Radio Shack, piece of technology is about 30 years old.  Of course nowadays calculators are becoming less common with the availability of scientific calculators on the mobile phone, though I still prefer to use my trusty Tandy.

I also remember when it was possible to buy digital watches with calculators, handy for working out your change in the pub, I suspect this has now been resurrected with the ubiquitous smart watch.