Factors and Factorising

Year 9 have been looking at simplifying algebraic fractions. They have spent the last half term looking at Fractions, Decimals and Percentages and the last few weeks expanding and factorising expressions so I thought I showed them the following and then next lesson the series of TRUE or FALSE statements. I thought that this would be a good idea to help students understand why some fractions can be simplified and others can’t. I have wondered if it might be a good idea to use the “factors” slides in my next lesson on factors as and extension of the basic idea of 7 is a factor of 35 etc.

Surface Area and Volume of Cylinders

I have been thinking a lot about a recent interaction on Twitter and how teachers calculate the surface area of a prism. I really liked the idea of looking at the areas of the cross sections (especially as it linked to volume of a prism) and adding the area of the net of the “tube” so, multiplying the perimeter of the cross section by the length. I have played around with a similar format I used for surface area recently and it worked well but I think I like to now move the students to using this approach. Plus I’d like them to practice volume alongside surface area so they can distinguish the two.

Interaction above

I made this after speaking to @MRSEVCartwright

Thanks to @mathsteacher09 for the suggestion of using circles not side elevation images for the area of the cross section