Tuesday, 11 October 2011

The problem with Powerpoint for teaching maths

There are a lot places on the internet where the are negative opinions about Powerpoint.  I don't want to repeat these arguments here, instead I wish highlight particular problems relating to the use of Powerpoint in the teaching and learning of mathematics.  These are that:
  • It reinforces a view of mathematics that it is a series of algorithms to be rote-learned;
  • It can reduce the amount of student-centred use of ICT in learning mathematics;
  • It is usually a static form of mathematics and there are many easy tools for creating equivalent dynamic forms of mathematics.
Reinforcing a limited perception of mathematics
Many Powerpoint presentations for mathematics feature a question with the stages of a solution presented.  This can have a negative impact of students' perceptions of mathematics.  There is a link between students' perception of mathematics and how successful they are.  Students who perceive maths a series of unrelated recipes for solving problems are less successful than those who see it as series of related ideas.  Displaying a single, predetermined method to solve a problem can reinforce the perception that mathematics is about learning the method for each type of question which reinforces the perception of it being about unrelated recipes that need to be rote learned.

Similarly it doesn't allow space for students to ask "what if...?" type questions or to suggest alternative methods for solving a problem or opportunities for linking with other areas of mathematics.  For example if the question is "solve x² + 5x + 6 = 0" and the solution presented is to factorise the students may perceive there is no value to sketching the curve, completing the square or applying the quadratic formula, or possibly, and even worse, that they if they'd tried to solve it using one of these methods that they are "wrong".

Reducing the student-centred use of ICT
The potential that digital technologies, or ICT, can have in the mathematics classroom is widely acknowledged.  However, there is a danger that using Powerpoint as a presentational tool can be seen as fulfilling this requirement and consequently additional, more powerful uses of ICT, such as student-centred use of ICT, may be overlooked. This is missing a huge potential given the impact student-centred use can have on learners' understanding when compared to passively watching a presentation. 

It is easier to produce a dynamic version of mathematics
The mathematics presented in powerpoint is static: if there is a function this cannot be altered easily in the presentation.  By contrast if the function is created in mathematical software it will be easy to alter.  For example, in teaching the relationship between the roots of a quadratic equations and the factorised form, it is straightforward to graph a quadratic function and observe the relationship between the equation and the intersections with the axis.  Not only does this provide a more generalisable demonstration of the relationship, it is easier to do than producing a powerpoint.