As for our most recent WitCH, this one comes from *VicMaths*, Nelson’s Specialist Mathematics Year 12 text. It is an exercise and solution from the Logic and Proof chapter (covering a new VCE topic). Continue reading “PoSWW 39: A One-Sided Triangle”

# Tag: inequalities

## The Two Missing Words on Robodebt

Yeah, “I’m sorry” would have been kinda nice. But those aren’t the missing words.

It was always too much to expect even a façade of contrition from Morrison or Tudge or Miller or Benson, or at least a dozen other down-punching sociopathic thugs. So, although the words of regret are blaring in their absence, the words were not to be expected, they’re not missing as such. The missing words are:

Well, duh. Continue reading “The Two Missing Words on Robodebt”

## Witch 100: The Inequality of Robodebt

We were hoping for a special for our hundredth WitCH, but the chips fall when they fall. Still, it’s an odd one.

Robodebt is one of the greatest perversions of politics and public administration in Australian history. It is now reaching its appalling conclusion with the Royal Commission‘s hearings, a grotesque procession of half-wits, cowards and sociopathic goons. Rick Morton, and pretty much only Rick Morton, has covered the just-ended hearings in maddening and heart-rending detail. We only await Commissioner Holmes’s inevitably damning report.

We had pondering writing something on Robodebt, just to add our public declaration of disgust, and if only to employ the expression “Little Eichmanns”. But, we could see no natural angle. Now, however, a statistician has provided a different angle.

## Accentuate the Negative

Each year about a million Australian school students are required to sit the Government’s NAPLAN tests. Produced by ACARA, the same outfit responsible for the stunning Australian Curriculum, these tests are expensive, annoying and pointless. In particular it is ridiculous for students to sit a *numeracy *test, rather than a test on arithmetic or more broadly on mathematics. It guarantees that the general focus will be wrong and that specific weirdnesses will abound. The 2017 NAPLAN tests, conducted last week, have not disappointed. Today, however, we have other concerns.

Wading into NAPLAN’s numeracy quagmire, one can often find a nugget or two of glowing wrongness. Here is a question from the 2017 Year 9 test:

*In this inequality *n *is a whole number.*

*What is the smallest possible value for *n* to make this inequality true?*

The wording is appalling, classic NAPLAN. They could have simply asked:

What is the smallest whole number *n* for which

But of course the convoluted wording is the least of our concerns. The fundamental problem is that the use of the expression “whole number” is disastrous.

Mathematicians would avoid the expression “whole number”, but if pressed would most likely consider it a synonym for “integer”, as is done in the Australian Curriculum (scroll down) and some dictionaries. With this interpretation, where the negative integers are included, the above NAPLAN question obviously has no solution. Sometimes, including in, um, the Australian Curriculum (scroll down), “whole number” is used to refer to only the nonnegative integers or, rarely, to only the positive integers. With either of these interpretations the NAPLAN question is pretty nice, with a solution *n* = 10. But it remains the case that, at best, the expression “whole number” is irretrievably ambiguous and the NAPLAN question is fatally flawed.

Pointing out an error in a NAPLAN test is like pointing out one of Donald Trump’s lies: you feel you must, but doing so inevitably distracts from the overall climate of nonsense and nastiness. Still, one can hope that ACARA will be called on this, will publicly admit that they stuffed up, and will consider employing a competent mathematician to vet future questions. Unfortunately, ACARA is just about as inviting of criticism and as open to admitting error as Donald Trump.