Blog posts

Probability - Complement Approach2 June 2019

Question: Two fair six-sided dice are rolled. What is the probability that at least one of the dice shows a five facing up?Three different solutions are given below. Let X be the random variable representing... more

Worked Solutions - HL Paper 1 Exam22 May 2019

The May 2019 IB examination session is now finished. Teachers are eager to scrutinize an exam after it has been made available 24 hours after students have taken it. This usually leads to some interesting... more

Euler's method on the TI-Nspire17 March 2019

As they say, a picture (or a video, in this case) is worth a thousand words. The video here shows one way to use the spreadsheet on the TI-Nspire to perform Euler's method to find the approximate solution... more

what is path of midpoint of a falling ladder?24 November 2018

Something which I think that is often not emphasized or valued enough when teaching mathematics is encouraging students to visualize a graph, diagram, relationship between objects, motion of an object,... more

Effective GDC Use #317 November 2018

Concerning effective GDC use, I try to avoid giving my students the impression that mindlessly pushing buttons on a GDC will allow them to successfully answer an exam question. Although there may be exam... more

P.o.t.D.- 301 problems1 October 2018

This is just a short entry to highlight the fact that I have now managed to compose more than 300 problems in my Problem of the Day (P.o.t.D.) lists - one list for an SL Problem of the Day, and another... more

Effective GDC Use #220 September 2018

Continuing my discussion on promoting effective and wise use of a calculator (GDC) by our students, I wish to highlight what I consider maybe the first and simplest piece of GDC advice to students: “When... more

Effective GDC Use #112 September 2018

The region R is enclosed by the graph of $$y = {\rm{\pi }} - 3\arccos \left( x \right)$$, the y-axis and the line $$y = 2$$.(a) Write down a definite integral to represent the area of R. [4] more

P.o.t.D.- 250 Problems7 May 2018

I started writing problems for my Problem of the Day (P.o.t.D.) section on this site 15 months ago - and there are now 250 problems available - equally distributed between HL and SL. The distinction between... more

Some fun with primes ... and Geogebra18 January 2018

Prime numbers are fascinating, mysterious and useful. The topic of prime numbers can pop up in a maths lesson at many different ages and ability levels. The announcement two weeks ago of a ‘new’... more