If "death by PowerPoint" was an actual disease, most of my students would not make it to October half-term. I use the application in every maths lesson I teach.
In recent years there has been a trend away from PowerPoint to the software that comes with Promethean or SMART interactive whiteboards, and most people reading this will have been subjected to in-house interactive whiteboard training. And on the surface, it all looks very impressive. There are ready-made grid lines for drawing graphs, there is a circle tool and have you seen how you can pull down those fancy blinds to hide some of the screen? But if you want to write an equation - good luck!
Yet most of these - with the exception of handwriting recognition - you can do on PowerPoint. Copy and paste some graph paper off the internet (or better still, use Autograph), insert a circle, and if you want to hide something just pop it on the next slide.
Now I know what you are thinking: all the worst presentations you have ever seen involved PowerPoint. Furthermore, some of the worst lessons I have watched involved PowerPoint.
But there is a right and wrong way to use the software in lessons. A common trait among teachers is to prepare lessons so that every note, every question, every worked solution is beautifully typed out on PowerPoint. Well, all it takes is for a student to ask an unanticipated question, or to offer an alternative correct answer to the one that took an hour to create using Equation Editor, and your carefully planned lesson is in pieces.
PowerPoint works best when it improves the flow of the lesson. My presentations tend to include notes or diagrams I want the students to copy, as my writing is terrible. I can then use the time to help any students having difficulties, and from a behaviour-management perspective I don't have my back to the class. I also like to type up questions, but leave the rest of the screen blank so I can use the pen tool to make a note of all the different approaches and responses my students make. Better still, they can come to the front, choose the colour of their electronic ink, and share their answers.
And when the lesson is finished, I always do the same thing - when the computer asks if I would like to add the drawings I have made to my presentation, I say yes. That way, as well as my original file I have a record of how the lesson progressed that I can use next time I teach the topic. Better still, if any students missed the lesson, or want help with revision, I can email the PowerPoint to them, complete with handwritten notes.
So yes, I am a big fan of PowerPoint in maths lessons. (And if you're reading, Bill Gates, and want to give me a few million to promote it, just drop me an email.)