It can't be true... can it?
Yes, it is indeed true that the square root of 2 and two thirds is equal to 2 times the square root of two thirds. This particular equation is an example of a prompt
on the UK-based website Inquiry maths
. The website explains:Inquiry maths is a model of teaching that encourages students to regulate their own activity while exploring a mathematical statement (called a prompt). Inquiries can involve a class on diverse paths of exploration or in listening to a teacher's exposition. In inquiry maths, students take responsibility for directing the lesson with the teacher acting as the arbiter of legitimate mathematical activity.
Remarkably, this particular prompt was found by a year 10 student of teacher Rachael Read
. It is recommended for students with high prior attainment in years 10 and 11. Reportedly, students are quickly hooked in to the prompt, particularly when one of them claims it “works” after checking on a calculator. Relevant links
There is more discussion of the educational value of this equation, and on the teaching of surds in general, in the original blog post on this topic: http://www.inquirymaths.co.uk/home/number-prompts/surds
The word “surd”, referring to n-th roots, is a Latin translation of a term tracing back to the 9th century Persian mathematician al-Khwārizmī
, after whom algorithms
are named. He also invented the term algebra
(al-jabr in Arabic).
(Seen via Cliff Pickover on Twitter.)#mathematics #education