Prehistoric calculators

With all the gizmos that we are using nowadays, it's hard to imagine how life was only a few decades ago when we were using what we now consider 'prehistoric' equipment. I once visited the Smithsonian Museum in Washington DC and saw the first computer created in the 1950s - it covered at least 5 large rooms. Today we have something much better in the palm of our hands. Calculators have also come a long way, and today I share with you three photos of old adding-machines which I found displayed in a small museum in St Gertrude's church in Cottonwood, Idaho. Today people have calculators on their watches!