Percentages with Ratio Tables

What if I said you could teach your students one thing and they could answer everything to do with Percentages?

Don't believe me?

Let me show you:

Finding a percentage of an amount

Q: Find 20% of 925

Increasing/Decreasing by a percentage

Q: Decrease 45 by 16%

Expressing as a percentage

Q: A cereal bar weighs 24g. The cereal bar contains 3.6g of protein. Work out what percentage of the cereal bar is protein

Percentage Change

Q: Rebecca bought a dress for £80. She later sold it for £116. Find the percentage profit.

Reverse Percentages

Q: A car increases in value by 35% to £2500. What was its original price?

Ratio tables can be used for it all. There is obviously going to need to be some further teaching about what an increase/decrease is, how to work out the multiplier etc, but it is a great tool we should all be using more often

You may have worked out by now that I like using Ratio tables.

📝 Weekly Report #21

The trainee teacher in our department has started to teach my Year 10 group this week. It has taken me back to when I was training and the struggles that I had and the feedback my mentor would give me. One thing I didn't consider back then was how the class teacher feels who I was taking over from. I know that as a trainee I was no where near being an amazing teacher but over time I have continually improved. So it has been a struggle for me to allow the trainee to teach my class thinking that there would be aspects that I know I could deliver much better. On the flip side of this it has been great to learn from him by watching him teach and being able to give small steps to improve for next time. The initial focus has been on general pedagogy, e.g. use of questioning, planning for misconceptions etc. It's made me reflect on my own teaching ensuring I don't just talk it, I walk the walk too! I've also enjoyed seeing the improvements he has been able to make lesson on l...

📝 Weekly Report #7

👨‍🏫 Teaching: Colin Hegarty has recently been posting questions from Sparx and discussing which questions are better to use and why. Check out some of his tweets here . It got me thinking about the questions and examples I use in my own teaching, in particular around the numbers I choose to use. It highlights the need to carefully craft questions to pull out misconceptions and ensure students are learning the concept correctly rather than getting to the answer by chance. Unfortunately time is precious and so it is very difficult to do this for every question in every lesson I teach. Having said that, I have made a conscious effort to ensure the examples I am using are there on purpose and can be used to highlight key concepts so students can generalise ideas more easily. Will definitely look into this more as part of my NCETM course throughout the year. Definitely given me lots to think about to improve my teaching. 🔊 Listen: High performance podcast with Mark Cavendish. Mark t...

Ratio Tables: Why you need to use them?

Only 36% of students were able to answer the question on the right. Whereas 75% of students were able to correctly answer the problem on the left. (7) Why? What's the big difference? Students are more likely to relate values between objects (left question) than within an object (right question). (7) A similar issue comes up in the questions below. 91% getting the bottom question correct, relating 11 people to 33 people. Whereas only 51% answered the top question correctly. Students often struggle to see all of the multiplicative links between and within values. One of the misconceptions my own students had with the right 'L' question was that the answer was 45. They had added 13cm because 8 + 13 = 21 on the base of the 'L'. "Young children tend to see multiplication additively" Dietmar Kuchemann DfE suggests teaching multiplication as repeated addition, with arrays, in Yr2. Yr3 scaling is introduced but after that isn't mentioned again. It is as...

Cameron Setter

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