This goes from the very early use of counting to the marvellous ‘place-value’ system in use today. This system is sometimes credited to the Arabic world over a thousand years ago, sometimes to India and China some two thousand years ago, but was invented by the Sumerians more than four thousand years ago. Only in the 20th century was this fully understood, and the concise nature of their floating-point, base-60 system made it a wonderful vehicle for calculations. My talk in Sweden https://www.youtube.com/watch?v=piQV8QCB7os