Exploring decimal time

During revision on standard units with Year 9 this week, we dealt with the typical confusions between metric and Imperial – they’re fairly happy with metres and centimetres, but a few are also convinced that inches and feet are too, possibly because they’re still in such common usage.A question that one pupil had was about time – namely whether the analogue 12-hour clock was Imperial and the digital metric. His reasoning was that, similarly to feet, inches and ounces, the analogue clock was “old-fashioned”. I put him straight, but it did get me thinking about the idea of decimal (base 10) time – it’s always an interesting discussion when you’re teaching factors and multiples to ask pupils to think about why we use base 12 for a clock and why there are 60 minutes in an hour.
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To satisfy my curiosity, I went Googling and read a very interesting article that confirms that decimal time was considered and briefly summarises the principles behind it. If you’re teaching units of measurement soon, it’s worth a read.
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(Image: By shakko – Own work, CC BY-SA 3.0, commons.wikimedia.org/w/index….)