LOTW - Expressions using algebra tiles

Linking algebraic expressions, words and pictorial representations

Year 9 and I have been working on algebraic expressions this week, and the lesson I taught yesterday was successful enough to deserve a "Lesson of the Week" post.

We did the Standards Unit card sort earlier in the week, which was far more successful than usual, possibly because I attempted to structure the activity far more than I have done before. After a starter on area of a rectangle, the pupils sorted out the diagram set first, copied these into their books and worked out the area using their own terms before then matching the words and algebraic expressions.

Yesterday, I'd photocopied this great resource from Tim Buckton and was planning to use it as a straightforward ten-minute cut and stick, but as I had a spare half-hour of PPA before the lesson, I decided to plan and try something a bit different.

Cutting, sticking, making a mess...

I'd not used algebra tiles with this group before, so I decided that this was an opportune moment to introduce them (you can read more about my love of algebra tiles here). I've found that some pupils can be quite resistant to using manipulatives at KS4, so I'm trying to get the tiles in early so my class are used to them to support all our work on algebra.

I started the lesson with a quick introduction / explanation of the tiles, with a couple of example diagrams. In order to emphasise the area links (and for later work on factorising), I demonstrated making a tile arrangement into the "best" rectangle I could.

After we'd done this bit, I gave each pupil a pack of tiles and the card sort, spacing them out one per desk so they didn't get all their cut-out bits and diagrams mixed up with their partner's.

The activity worked really well in terms of engagement for most, and I had lots of discussions with individual pupils revealing and quashing lots of common misconceptions.

We addressed:

• x + 3 is not the same as 3x
• x^2 is not the same as 2x
• The interpretation of 2(x + 3) as "2 lots of x + 3" - physically finding x + 3, then finding another lot, then putting the two lots together.

I'm planning to explore the area idea in a little more depth next week. You can get the slides for this lesson here.

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