For the next fortnight, we’re going to be learning about algebra. This is where letters and other symbols (often a, b, x, y and z) are used to represent numbers. Here’s an introduction to why mathematicians do this from the Khan Academy:
There are lots of other introductory videos in the algebra section on the Khan Academy website. They are all interesting in their own way but include sections that may be difficult to follow and so we’re not posting them here. But they are certainly something that you could look at yourselves after the lessons, if you want to, and even include one describing the origins of algebra in the Middle East and India more than a 1000 years ago.