I worked out my bank balance recently and of course used a calculator, although it was hardly worth it for my miserable balance!
Over the years a word can travel far from its original meaning, and Latin calx meant a stone. Using stones for counting was practical, and calculator and calculus derive ultimately from this.
Another Latin word scrupulus - a small sharp stone - is interesting, too. Over time scrupulus came to mean pain, like having a stone in your shoe. The connected scrupulosus gradually took on two meanings; sharp or rocky and also careful, like a man walking on rocky ground. Modern English scruple - moral consideration - and scrupulous, as in scrupulous attention to detail developed from these. A long way from the original meaning of 'stone', but there's an old English measure called a scruple, used by pharmacists to measure small amounts of medicine, similar in weight to a small stone.
Still on stone - the English to this day measure body-weight in stones. A 'stone' weighs 14 pounds, 6.35k, and although most people understand kilos nowadays, older people still feel happier saying 15 stone 10 pounds than the American 220 pounds or 100 kilos as most of the world says. Somehow it sounds less.
Metre came from the French; rightly so, since the metric system was devised by them. The Anglo-American yard, though, has had a tremendous journey through time to the present day. It is connected with Latin hortus, meaning garden and to an even earlier Sanskrit word and came to us through Germanic languages. Its original meaning was an enclosed space and you can still see this in yard meaning the small area behind your house. Gradually, it also became a unit of measure - a little less than a metre - and Anglo-Saxons are still comfortable with the word, although the metric system is taking over. Similarly, foot is still common in American and British English - it is a third of a yard and has twelve inches in it. Anglo-Saxons usually say they're six feet rather than 1.83 metres tall. Both foot and inch derive from Latin uncia meant a twelfth part of a pes, a foot.
Uncia also gives English ounce, a sixteenth of a pound in weight. But hang on, why sixteen, not twelve? Well, two weighing systems developed.
One, the troy system, used today for measuring gold, from the French town 'Troyes', had twelve 'ounces' but another system avoirdupois, from French having weight and still common in Anglo-Saxon countries, used a larger measure for a pound and was divided into 16. The troy ounce and the avoirdupois ounce are different in weight even today.
Confused? Don't worry. It confuses us Anglo-Saxons, too, and the day will surely come when all measurement will be metric.
I caught myself counting the other day on my fingers - and it's from Latin that our medical and mathematical word digit comes, bypassing the connected French word doigt for finger. A digital watch shows numerals not hands. The French use their word for thumb to mean an inch. English doesn't, but does use the word hands to indicate the height of a horse at the shoulder - a hand means 4 inches. But fingers and hands have always been used for counting and measuring.
Measuring small things was difficult in early times, and grain as in grain of sand and a small morsel of cereal came to be used in medical measurement - it is very small - only 64mg. Weighing precious jewels and gold was problematic, too. But ancient jewellers found the carob seed approximated to the weight of the smallest gemstone. The seed was called a carat and came to us through Arabic from Greek and meant small horn, the shape of the seed pod. Now carat means a weight of 200mg in gemstone measurement. Carat is often confused with karat, which, though from the same source, refers to a unit of pure gold in an alloy equal to one-twenty-fourth of the entire weight. So, if you buy your wife a 22 karat gold ring, then it is 22 parts pure gold and 2 parts of another metal. Laymen understandably confuse carat and karat but jewellers talk of 18K gold, yet always write carat in full.
Beer is measured in fluid ounces, pints, decilitres and litres. But I don't care, as long as the beer I am going to have now is a large one. Cheers!