Catriona Agg
@catrionaagg.bsky.social
Maths teacher. I aim to share lots of snippets of my lessons using #MathsToday and would encourage you to do the same!
Also occasional geometry puzzles 🧩
Also occasional geometry puzzles 🧩
I was rubbing this off the board as Y7 came in for the next lesson, and two of them asked why I was teaching discrimination in maths. (I told them they’d have to do A Level to find out!)
November 21, 2025 at 6:00 PM
I was rubbing this off the board as Y7 came in for the next lesson, and two of them asked why I was teaching discrimination in maths. (I told them they’d have to do A Level to find out!)
I used some of the statements from undergroundmathematics.org/quadratics/d... as a starter for Y12 before moving onto the discriminant. It was a nice excuse to get them using sliders and reasoning about graphs in order to reason about equations. #ALevelMaths #MathsToday
November 21, 2025 at 5:57 PM
I used some of the statements from undergroundmathematics.org/quadratics/d... as a starter for Y12 before moving onto the discriminant. It was a nice excuse to get them using sliders and reasoning about graphs in order to reason about equations. #ALevelMaths #MathsToday
The other advantage of real data is that I feel like it helps drive home the first two bullet points, and hence avoid complacency from students who think they’ve already done the hard work.
November 19, 2025 at 5:20 PM
The other advantage of real data is that I feel like it helps drive home the first two bullet points, and hence avoid complacency from students who think they’ve already done the hard work.
In lieu of grade boundaries, I showed them these histograms, of previous students grouped by the grade they ended up with. Took a bit of explaining, but I hope it helped them see what they were on track for, without me having to give them an explicit grade. #MathsToday
November 19, 2025 at 4:43 PM
In lieu of grade boundaries, I showed them these histograms, of previous students grouped by the grade they ended up with. Took a bit of explaining, but I hope it helped them see what they were on track for, without me having to give them an explicit grade. #MathsToday
I was giving back mock papers in #MathsToday. I regretted reusing this slide from last year when a decent number of them started sniggering at my choice of grades. Apparently even Y11 still find this funny!
November 19, 2025 at 4:36 PM
I was giving back mock papers in #MathsToday. I regretted reusing this slide from last year when a decent number of them started sniggering at my choice of grades. Apparently even Y11 still find this funny!
❤️ Love this ❤️
@mathforge.org has done what I’ve never been organised enough to do myself, and catalogued every #geometrypuzzle I’ve ever posted on social media. It looks amazing!
@mathforge.org has done what I’ve never been organised enough to do myself, and catalogued every #geometrypuzzle I’ve ever posted on social media. It looks amazing!
November 17, 2025 at 6:33 AM
❤️ Love this ❤️
@mathforge.org has done what I’ve never been organised enough to do myself, and catalogued every #geometrypuzzle I’ve ever posted on social media. It looks amazing!
@mathforge.org has done what I’ve never been organised enough to do myself, and catalogued every #geometrypuzzle I’ve ever posted on social media. It looks amazing!
Y13 did their first set of integration looky-likeys in #MathsToday. Looking forward to lots more of this in the next few weeks!
The last one was a bit mean (I put it there to slow down the fast finishers) but they did manage it when I gave them the right substitution. #ALevelMaths
The last one was a bit mean (I put it there to slow down the fast finishers) but they did manage it when I gave them the right substitution. #ALevelMaths
October 20, 2025 at 7:37 PM
Y13 did their first set of integration looky-likeys in #MathsToday. Looking forward to lots more of this in the next few weeks!
The last one was a bit mean (I put it there to slow down the fast finishers) but they did manage it when I gave them the right substitution. #ALevelMaths
The last one was a bit mean (I put it there to slow down the fast finishers) but they did manage it when I gave them the right substitution. #ALevelMaths
This lesson was also helped by the fact that I included integrals when we made these notes on differentiation a couple of weeks ago, so today we had some examples to refer back to. I even managed to keep the same colour scheme going! #ALevelMaths
October 15, 2025 at 4:38 PM
This lesson was also helped by the fact that I included integrals when we made these notes on differentiation a couple of weeks ago, so today we had some examples to refer back to. I even managed to keep the same colour scheme going! #ALevelMaths
Today I realised that “integrates like” is the phrase I’ve been missing for talking about spotting the structure of an integral. #ALevelMaths #MathsToday
October 15, 2025 at 4:32 PM
Today I realised that “integrates like” is the phrase I’ve been missing for talking about spotting the structure of an integral. #ALevelMaths #MathsToday
I thought Y7 might need a warm up to the task in the first picture, so I modelled a couple and got them to try their own numbers on MWB. Brilliantly, someone happened to get 23, 24 and 23. After such a near miss they were all very motivated to try and get a perfect triplet! #MathsToday
October 14, 2025 at 8:33 PM
I thought Y7 might need a warm up to the task in the first picture, so I modelled a couple and got them to try their own numbers on MWB. Brilliantly, someone happened to get 23, 24 and 23. After such a near miss they were all very motivated to try and get a perfect triplet! #MathsToday
Really enjoyed today’s Y7 lesson: linking function machines, telling the ‘story’ of a variable, substitution and sequences, in order to generate sequences from an expression. I love these lessons when it feels like everything comes together! #MathsToday
October 9, 2025 at 5:42 PM
Really enjoyed today’s Y7 lesson: linking function machines, telling the ‘story’ of a variable, substitution and sequences, in order to generate sequences from an expression. I love these lessons when it feels like everything comes together! #MathsToday
The main aim of this session was really to get teachers using this framework to discuss which representations they would use and when. But colouring in is always a bonus.
An interactive version of the representations is here: www.desmos.com/calculator/3...
An interactive version of the representations is here: www.desmos.com/calculator/3...
October 8, 2025 at 8:26 PM
The main aim of this session was really to get teachers using this framework to discuss which representations they would use and when. But colouring in is always a bonus.
An interactive version of the representations is here: www.desmos.com/calculator/3...
An interactive version of the representations is here: www.desmos.com/calculator/3...
In #MathsToday I made 40 A Level teachers colour in representations of the binomial distribution.
This is your regular reminder that if you teach #ALevelMaths you should definitely try to join your local Maths Hub’s A Level Pedagogy group. There is some brilliant stuff going on all over England.
This is your regular reminder that if you teach #ALevelMaths you should definitely try to join your local Maths Hub’s A Level Pedagogy group. There is some brilliant stuff going on all over England.
October 8, 2025 at 8:18 PM
In #MathsToday I made 40 A Level teachers colour in representations of the binomial distribution.
This is your regular reminder that if you teach #ALevelMaths you should definitely try to join your local Maths Hub’s A Level Pedagogy group. There is some brilliant stuff going on all over England.
This is your regular reminder that if you teach #ALevelMaths you should definitely try to join your local Maths Hub’s A Level Pedagogy group. There is some brilliant stuff going on all over England.
I used this prompt with two Y8 classes today. In the 1st class their initial reactions were pretty evenly split between all the options. The 2nd class are higher-attaining mathematically, and the vast majority confidently went for £100. #MathsToday
October 3, 2025 at 8:11 PM
I used this prompt with two Y8 classes today. In the 1st class their initial reactions were pretty evenly split between all the options. The 2nd class are higher-attaining mathematically, and the vast majority confidently went for £100. #MathsToday
Highlight of today was showing Y8 how they could use prime factors to simplify ratios. I was impressed that they remembered that when all the factors are cancelled out it would simplify to 1 - I was expecting most of them to write 0 #MathsToday
September 12, 2025 at 6:33 PM
Highlight of today was showing Y8 how they could use prime factors to simplify ratios. I was impressed that they remembered that when all the factors are cancelled out it would simplify to 1 - I was expecting most of them to write 0 #MathsToday
Wednesday was a very quiet day for me, but I enjoyed playing investigators with Y7. Everyone had to write a sequence that began 10,20… and then we tried to guess the rule that they had used. #MathsToday
September 12, 2025 at 6:33 PM
Wednesday was a very quiet day for me, but I enjoyed playing investigators with Y7. Everyone had to write a sequence that began 10,20… and then we tried to guess the rule that they had used. #MathsToday
Tuesday’s lesson with Y12 was something no we talked about lots in last years A Level Pedagogy Work Group - the importance of explicitly teaching pupils how to sketch graphs. Was also good to teach them Desmos skills like rescaling the axes. #MathsToday #ALevelMaths
September 12, 2025 at 6:33 PM
Tuesday’s lesson with Y12 was something no we talked about lots in last years A Level Pedagogy Work Group - the importance of explicitly teaching pupils how to sketch graphs. Was also good to teach them Desmos skills like rescaling the axes. #MathsToday #ALevelMaths
On Monday I got Y13 to find the turning points of these graphs as an intro to the chain rule. Partly because I like how sketching is so much better than the ‘obvious’ expand and differentiate, but also to make the point that we can use the extra structure to our advantage. #MathsToday #ALevelMaths
September 12, 2025 at 6:33 PM
On Monday I got Y13 to find the turning points of these graphs as an intro to the chain rule. Partly because I like how sketching is so much better than the ‘obvious’ expand and differentiate, but also to make the point that we can use the extra structure to our advantage. #MathsToday #ALevelMaths
Spent a slightly painful 15 minutes discussing Q2 with Y12 today. The problem wasn’t with spotting the patterns, but trying to formulate that into full sentences. If you teach #ALevelMaths, I’d be interested to know how your students get on with similar “describe and explain” tasks. #MathsToday
September 5, 2025 at 7:40 PM
Spent a slightly painful 15 minutes discussing Q2 with Y12 today. The problem wasn’t with spotting the patterns, but trying to formulate that into full sentences. If you teach #ALevelMaths, I’d be interested to know how your students get on with similar “describe and explain” tasks. #MathsToday
Taught my first #MathsToday lessons of the year! I forgot how much fun this topic is with Year 7. Today we played “guess the method from the calculation”.
September 4, 2025 at 5:00 PM
Taught my first #MathsToday lessons of the year! I forgot how much fun this topic is with Year 7. Today we played “guess the method from the calculation”.
I asked Y8 what they thought the typical wage was from this list and was impressed by their suggestions! They even came up with the midrange, and were pleased to find out it had a name.
Followed up with an averages classic! #MathsToday
Followed up with an averages classic! #MathsToday
July 11, 2025 at 5:08 PM
I asked Y8 what they thought the typical wage was from this list and was impressed by their suggestions! They even came up with the midrange, and were pleased to find out it had a name.
Followed up with an averages classic! #MathsToday
Followed up with an averages classic! #MathsToday
Y8 are doing area, so I got to use the ‘plan without numbers’ approach for compound area that worked so well last year. This year’s class are much more confident, but still struggled at first to describe what the purpose of their calculations were, rather than just the mechanics of it. #MathsToday
July 5, 2025 at 3:09 PM
Y8 are doing area, so I got to use the ‘plan without numbers’ approach for compound area that worked so well last year. This year’s class are much more confident, but still struggled at first to describe what the purpose of their calculations were, rather than just the mechanics of it. #MathsToday
Y9 have been moving from frequency trees to probability trees. This sequence worked really well on MWB where they could change their previous answer each time - I’d definitely teach it this way again #MathsToday
July 5, 2025 at 3:04 PM
Y9 have been moving from frequency trees to probability trees. This sequence worked really well on MWB where they could change their previous answer each time - I’d definitely teach it this way again #MathsToday
A #MathsToday catch-up post: here are some of the things I’ve done this week.
Y10 learned about recurring decimals, so I used this Don Steward task (reformatted to remove fractional indices). I didn’t realise how nice the answers would be! donsteward.blogspot.com/2017/02/recu...
Y10 learned about recurring decimals, so I used this Don Steward task (reformatted to remove fractional indices). I didn’t realise how nice the answers would be! donsteward.blogspot.com/2017/02/recu...
July 5, 2025 at 2:10 PM
A #MathsToday catch-up post: here are some of the things I’ve done this week.
Y10 learned about recurring decimals, so I used this Don Steward task (reformatted to remove fractional indices). I didn’t realise how nice the answers would be! donsteward.blogspot.com/2017/02/recu...
Y10 learned about recurring decimals, so I used this Don Steward task (reformatted to remove fractional indices). I didn’t realise how nice the answers would be! donsteward.blogspot.com/2017/02/recu...
July 5, 2025 at 11:03 AM