Liz Truss’ historic maths tweet reveals something about the Tory leadership race

Last week a colleague sent me a historic tweet from one of the candidates for the leadership of the Conservative Party, Liz Truss. It read: “Next ,[sic] let’s replace ‘number’ and‘shape’ [sic] in Maths curriculum with proper terms like ‘arithmetic’ and ‘geometry’.”

It was part of a Twitter tirade about curriculum reforms from December 2011. Truss wrote it at a time when she was closely aligned with then education secretary Michael Gove. It preceded, by a few months, her appointment as parliamentary under-secretary to his department.

It smacks of Truss throwing out dog-whistle policies – through ultimately ill-informed tweets designed to attract controversy and appeal to a Conservative base – in order to elevate her position in government. There are strong parallels to the current leadership contest.

Until recently her tweet had languished with fewer than 10 likes over the course of a decade. But it shot to prominence last week when quote tweeted by comedian and physics graduate Dara Ó Briain. “Are ‘numbers’ not proper maths any more? Are ‘shapes’ woke?” he asked.

The replies are peppered with pithy one-liners about the communist nature of circles – shunning elitism by ensuring that every point is always equidistant from the centre, Conservative budgets being based on imaginary numbers or the only acceptable shapes to the Tories being right-angled triangles. There are even some more subtle jokes about looking forward to when we are released from the shackles of foreign mathematics and can determine our own rules under UKclidean geometry (as opposed to EUclidean geometry).

One eagle-eyed education fan went so far as to screen-grab Truss’s tweet and to highlight its multiple grammatical mistakes. Since the tweet is trying to make a point about academic rigour, it’s surprisingly poorly written.

But what about the substance of the tweet? Does it even make sense? Well “number” and “arithmetic” are not very good synonyms for each other. Neither are “shape” and “geometry”. Numbers are objects we use to count – typically some of the first mathematical concepts we encounter as children. Arithmetic, on the other hand could be described as the tools we use to manipulate and transform numbers.

At a push, you might describe number as an arithmetic value used to represent a particular quantity, but that might be stretching things. Similarly, we traditionally think of geometry as a branch of maths that deals with the properties, measurements and relative positions of points, lines, angles, curves and surfaces. Shape is just one concept from geometry.

To make the difference extra-stark, try substituting the words in a sentence: “The NHS is in really bad geometry.” For example. Or: “The Conservative government have done an arithmetic on it.” I am being facetious, of course, but the point remains. Number and shape might be amongst the earliest concepts that children meet in mathematics – a familiar way to introduce more complex topics in the subject, but no one has ever suggested abandoning the terms “arithmetic” and “geometry”.

Both sets of terms appear on the school curriculum, even at primary level. It wouldn’t make sense to swap the names of the branches arithmetic and geometry for objects within each area. They clearly mean different things.

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This is something that Truss must have known when she wrote her tweet. Despite not having studied higher mathematics herself, she could have asked her father John who was a professor of pure mathematics at Leeds University. He would have been able to put her straight on the nomenclature, as he would no doubt love to do on many of the more extreme policies she has recently announced as part of her leadership campaign. Newspaper reports during the run-off have suggested that left-leaning Truss senior, is “appalled” at her “conversion to extreme right-wing politics”.

Indeed, the contest to see who will become our next prime minister increasingly looks like a race to the bottom, with the candidates vying with each other to come up with the most discriminatory policy or the most prejudicial boast. And we will be forced to endure several more weeks of such scrabbling, at a time when the country desperately needs action to address the ongoing cost of living emergency and the equally pressing crisis facing the NHS.

Instead, it seems we will have to wait until at least 5 September, when we find out who has been able to get their sums right in order to convince the majority of the 0.3 per cent of our population who are eligible to vote in the leadership election that they should be the next prime minister. Until then, it remains to be seen who will geometry-up and find themselves moving into arithmetic 10 Downing Street.

Kit Yates is a senior lecturer in the Department of Mathematical Sciences and codirector of the Centre for Mathematical Biology at the University of Bath