#Calculator August 24

by Coach4aday · August 24, 2026

We may earn money or products from the companies mentioned in this post.

August 2026 several of us are going to take on the 30-Day Plugged in Coach4aday Challenge. Each day, we will feature an item from home or office that requires being plugged into a source of electricity to operate. We will reflect on how it makes life easier. For Day 24 it is the Calculator.

I have visited a few businesses that still have a desktop mechanical calculator on display. It is another tool that has been transformed by electricity.

Day 24-Calculator

Mechanical calculators were widely used by accountants long before electronic calculators existed. In fact, accounting and bookkeeping were major markets for mechanical calculating machines.

Timeline

1640s – Pascal: Blaise Pascal developed the Pascaline, an early mechanical adding machine. It was primarily designed to help with his father’s tax-accounting work.
1820s – Arithmometer: Charles Xavier Thomas de Colmar developed the Arithmometer, one of the first commercially successful mechanical calculators. It could add, subtract, multiply, and divide.
Late 1800s: Mechanical adding machines became increasingly common in banks, businesses, and accounting offices.
1880s–1920s: Companies such as Burroughs, Comptometer, and Marchant produced machines specifically useful for accountants, bookkeepers, and businesses.
1930s–1950s: Ten-key adding machines and more sophisticated mechanical calculators became standard office equipment. Many accountants spent their days working with machines that could perform calculations much faster than doing them by hand.
1960s–1970s: Electronic calculators gradually replaced mechanical machines.