About cookies

The NCETM site uses cookies. Read more about our privacy policy

Please agree to accept our cookies. If you continue to use the site, we'll assume you're happy to accept them.


Personal Learning Login

Sign Up | Forgotten password?
Register with the NCETM

What Makes A Good Resource - What sort of custard are you?

This page has been archived. The content was correct at the time of original publication, but is no longer updated.
Created on 08 September 2009 by ncetm_administrator
Updated on 03 September 2010 by ncetm_administrator

What Makes a Good Resource

What sort of custard are you?

What sort of custard are you? - resource exampleResource description:
This involve students using the idea of making custard to manipulate and play with ratios to learn how to perform common processes, with the aid of an excel spreadsheet. I have used this with all years and abilities.

Download the resource (Excel)
Teacher comments:
Ratio can often be a fairly dry subject which involves mixing paint into to various different colours and shades with little or no discussion. I developed this as I’m a big believer in students discussing maths and struggling with problems.  I also wanted to get a hook so that when students struggle with some ratio problems I can just say “Custard!” and they should be ok.

What I did:
I start off by having this on the screen and getting students to discuss the problem.
Inevitably I hear that the ratios are the same because we have just added one to each custard. We then investigate if this is true by looking at equivalent ratios. Once we have established that they are not the same, I give the students other custards to discuss.

The next part of the activity is to tell the students that perfect custard is in the ratio of 4:1 milk to custard. This means that my birthday (made up of course) is perfect custard as its the 12th March or 12:3. I then ask the students to suggest other days that are perfect custard. I then ask students to tell me if they’re birthday is runny or thick custard. If I feel that the class can manage it I ask about 8 students to come to the front of the class and ask them their birthdays. I then ask the rest of the students to put them in order across the front of the classroom from runniest to thickest.


It always amazes how students get confused with equivalent ratios. I think that this activity helps to show students that you need to multiply all the numbers in a ratio by a constant, not add a constant to get one. I found that at first students were unwilling to throw themselves fully in to the activity at first, but really liked the personalisation of their own custard, particularly if they were thick custard. I also found that it was important to get the students explain all of their answers as they were prone to simply guessing or not thinking about their answers fully and giving incorrect ratios and justifications.

Secondary Resources
What makes a good resources - using the materials

Comment on this item  
Add to your NCETM favourites
Remove from your NCETM favourites
Add a note on this item
Recommend to a friend
Comment on this item
Send to printer
Request a reminder of this item
Cancel a reminder of this item



03 May 2010 20:58
When I open it I just click 'enable macros' on the request box that comes up. If you don't see the request box then you need to open Excel and go to the tools menu. Go to Macro > security and set it to medium. Now when you open the spreadsheet it should ask you whet you want to do...
03 May 2010 20:26
I am really keen to look at this but I am getting "security" messages about the macro????? Help! What should I do?
By tangotango
         Alert us about this comment  
25 March 2010 20:36
We are really keen for others to submit their own resource and reflections on the lesson. I feel this can be a really good way for us to share our theories, thoughts and pedagogies.
If anyone feels like contributing, please send to pete.griffin@ncetm.org.uk and we will publish the best ones.
By petegriffin
         Alert us about this comment  
08 November 2009 16:37
I love this idea! I've tried a similar approach with orange juice and lemonade for making orangade, but I prefer the way yours already has a definitive "best" ratio, the Excel resource and the "people maths" motivation of using pupils' birthdays. Thanks for sharing.
By brookes
         Alert us about this comment  
Only registered users may comment. Log in to comment