Help for an interview

[piano1]

I've been invited to an interview for the position of a Maths TA. As part of it, I need to deliver a 25-minute lesson on the surface areas of cuboids and triangular prisms for GCSE grade 3, targeting grade 4. I'm not sure how to plan a lesson aimed at this level as I'm applying to support the students and teachers, and usually, I would not need to do this.
Can someone help me please?

What's grade 3/4??
I did all my GCSE's with letter grades so is it C/D level or more A/B??

Are you confident that the post is TA support and not TA cover supervisor? IME lots of schools are using L3 TA's for cover now.

A maths TA may be asked to deliver lessons to small groups as part of intervention.

However, grade 3 students find surface area a tricky enough concept as it is (keep mixing it with volume) so having to do cuboids and triangular prisms in 25 minutes is a big ask.

How big is the group you will be teaching? And what year group?

Grade 3/4 is D/C.

Thank you

• I'd ensure a presentation that's clear and has the key info and a diagram (handouts are great)

Not sure if they have equations at the front of exam papers any more - of not try and think or research a rhyme to remember it

it has been told that their present level which is 3 targeting level 4.
There will be 4-6 students in that group.

Ok they need to know that:
Surface area means the area of all the surfaces
Units are cm squared (even though the shapes are 3D)
Area of a rectangle is length x width (they should know this!)
Area of a triangle is base x height / 2 (hopefully know this, but ask them before they need it to check)

The problem is translating a diagram of a 3D shape into the different shapes they need to work out the area of. I’d have props (e.g. tissue box is a good size) to help them realise that the front and back, top and bottom and two sides are the same area. If they can work out the area of each of the visible faces, they just need to double and add for the whole thing.
I like a worksheet like this one dryuc24b85zbr.cloudfront.net/tes/resources/7109615/image?width=500&height=500&version=1439945893142 that breaks it down for them.

Then same for triangular prism, 2 triangles which are the same, then 3 rectangles which usually aren’t.

Thank you for your suggestion!
Do I need to let them measure each side of the cuboid as an activity?

Is it enough time to do this activity ?

It depends on how clued up they are as to whether they get onto the triangular prism. If they’re, say, Y10, then they should have met it before and might proceed quite quickly, so have a worksheet with a mix of questions on for if they get through the broken down ones.

I wouldn’t get them measuring, too much faff.

Could you get a copy of a revision guide or online resource and condense that? BBC bitesize was good from memory

I'd use nets for the 3D objects-and do it with squared paper so they can easily see the areas.

Thank you very much for your help!

Take in some boxes of different sizes and let the pupils measure them and create a table with the measurements. They like interactive lessons in interviews.

If they are Y10 grade 3/4 they are likely to feel quite patronised at having to measure boxes. I’d steer clear of nets just because they might find it difficult to draw them.

Can someone give me a worksheet for surface area of triangular prisms please?

If you google ‘surface area of triangular prisms worksheet’ there are loads online. If you haven’t got a TES account it might be worth signing up (free) as there are some good ones on there that you can see on google images.