median
don steward
mathematics teaching 10 ~ 16

Friday, 27 December 2019

summing the cubes

Nicomachus appreciated this rule (~60 to 120 CE)

thanks to David Wells for the numerical approach

a ppt is here

this task can begin with an exploration of numbers
with a result being easy to find

it can be justifed using numbers

there is a novel diagrammatic representation

algebra can be tackled (if you can expand a cubic bracket) to justify the uniqueness of the first few results




a result that is needed later





see youtube

or nrich 325


how can you be sure that this process continues?



















an interesting alternative diagram
possibly using Cuisenaire rods




















algebra used to justify that you need to start at 1
(for the first two, three and four consecutive cube cases anyway)

the three consecutive cube case is easiest:




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