Blog posts

counting primes 2 December 2014

Even though they do not need to know it for any exam question, I think any student in IB Math HL or SL should be familiar with Euclid's famous proof of the infinitude of primes. The only formal proof... more

volume of a donut 19 November 2014

One of my students came up with - what I thought - is a good idea for an Exploration: finding the volume of a donut. Or, more precisely, deriving a general formula for the volume of a torus. The torus... more

Dealing with Infinity 2 November 2014

There comes a time in both Maths HL or Maths SL when probing questions about infinity will be confronted - by both teacher and student - or, at least they should be. This usually first occurs with the... more

Remembering Martin Gardner 25 October 2014

A few days ago (Tuesday 21 October) marked 100 years since the birth of Martin Gardner, one of the most influential American mathematics and science writers of the 20th century. Gardner was an extraordinarily... more

Is infinity a number? 24 October 2014

Today I wanted to quickly convince my Maths SL students that for any triangle the ratio of the length of a side to the sine of the angle opposite it is always equal to the ratio of another side of the... more

the invention(?) of logarithms 400 years ago 19 October 2014

In 1614, the Scottish nobleman, mathematician, scientist and theologian John Napier (1550-1617) published Mirifici Logarithmorum Canonis Descriptio (A Description of the Wonderful Law of Logarithms).... more

GDC - visual check ... solution? 7 October 2014

Today I posed a fairly common type of 'quadratic functions' question to my first year Maths HL students. The question is also suitable for SL students although questions like this are less common on SL... more

free graphing technology-1 28 September 2014

The decision by teacher and student on which graphing technology to use is a very important one. In some schools a teacher will have full control of the graphing technology used both by themselves in... more

Yang Hui's triangle 26 March 2014

Perhaps the most well-known two-dimensional number pattern is the triangular array of binomial coefficients most commonly referred to as Pascal's triangle. However, the pattern had been known and studied... more

GDC solution times - Specimen P2 question 2 March 2014

There has been quite of bit of interesting discussion going on recently in the Maths HL forum on the Online Curriculum Centre (OCC) with regard Question 5, part (b) on the most recent HL Specimen Paper... more