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← Thinking in Rates · Lesson 5 of 5

The pool deck

About it

Swimmers count pace per 100: the time for each hundred metres or yards. A swimmer who covers 400 metres in 6:00 holds 1:30 per 100, because 360 seconds shared across four hundreds is 90 seconds each.

A coach turns pace into a send-off: leave every 1:45 and a swimmer holding 1:30 per 100 rests 15 seconds before the next one. The pace clock on the wall counts to sixty, so the leaving times walk round the dial — the course The Pool Deck Is a Maths Room draws the shapes they make.

The figure

400 metres in four hundreds

1:301:301:301:30400 m in 6:00 = 360 secondsleave every 1:45: swim 1:30, rest 15 s
400 metres swum in 6:00, which is 360 seconds, drawn as four hundreds. Shared equally each hundred gets 90 seconds, 1:30 per 100. On a send-off of 1:45 the swimmer rests 15 seconds before the next one.
One question

A swimmer covers 200 metres in 3:20. What is their pace per 100 metres?

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