Over the course of the 2021/22 academic year, the GUESS method, was an essential tool for helping my pupils to solve equation-based problems in physics. The acronym ‘GUESS’ (Given; Units; Equation; Substitute; Solve) was used to lower pupil’s cognitive load, when it came to completing an equation-based task.

The GUESS method provides pupils with an appropriate scaffold that can be used every time they have to solve an equation-based problem.

It helps with:

· Selecting information from an exam question.

· Checking and converting units.

· Selecting the appropriate equation, rearranging equations and checking your final answer.

This method is now embedded in my teaching, it is very natural for me to use it in a physics lesson involving equations. KS4 pupils were quick to familiarise themselves with the method and responded well to me saying that, “it’s good to GUESS in physics!” Teachers have also embraced the method and it is now how equation based questions are taught across the whole department.

Searching for the winning acronym

There are alternative acronyms available and I searched to find if GUESS was the winning one.

The Physics teacher blog states:

‘The FIFA method is an AQA mark scheme-friendly* way of approaching GCSE Physics calculation questions. (It is also useful for some Y12 Physics students.)’

FIFA (F = Formula; I = Insert values; F= Fine tune; A= Answer), again provides pupils with an acronym to reduce cognitive load. However, I wasn’t as convinced with the language associated with the acronym. Fine tune seemed just a bit ill-defined to me.

‘FIFA isn’t a royal road to mathematical mastery (although it certainly is a better bet than the dreaded ‘formula triangle’ that I and many other have used in the past). FIFA is the scaffolding, not the finished product.’(The Physics teacher blog)

The FIFA method again lends itself nicely to Rosenshine’s principles of instruction, encouraging the scaffolding of equation-based problems, before trying to find a solution. Moreover, the method increases the willingness of pupils to have a go at these types of questions. Time is needed to embed these techniques.

I found there were lots of acronyms to help with the scaffolding of equation-based questions. However, again I didn’t believe they lent themselves as well to the learning of our BCA pupils.

When commenting on, The Physicsteacher blog, asking whether any other acronym was a better model, than using FIFA, I received the following response:

‘In the end, both are just mnemonics – the important thing is that the majority of students are engaging with calculations in a systematic, sustainable way. FIFA has generally worked really well in the schools I have worked in. If GUESS is embedded and working well in yours then, on balance, I would personally not change it: “If ain’t broke, don’t fix it.’

This summed it up nicely. Embrace the method that works for you and your department. No acronym is perfect, but for us, the winner of the acronym world cup was GUESS.

Troublesome Triangles

Furthermore, the GUESS method also removes the need for pupils to use formula triangles. There is a lot of commentary stating that formula triangles are a hinderance to pupil understanding and allow low expectations to creep in.

Why are they troublesome?

· They don’t teach students how to actually rearrange equations

· They don’t work for more complex equations such as

· They are no easier to remember than remembering and recalling the equation itself.

‘The formula triangle is misleadingly simple. As a result, it is often called upon by students in situations where it is an inhibition rather than a convenient bypass of mathematics.’ (Southall, Edward 2016)

The Physicsteacher blog also states that:

‘Formula triangles are bad news. They are a cognitive dead end.’

In fact, the ASE even advises against the use of formula triangles, even if they could be seen as a starting point, or easier for students:

‘Relying on their use means that pupils are not developing the skills to become fluent in rearranging different types of equations.’ (ASE 2016)

Therefore, using any scaffolding acronym method would be more favourable than the use of equation triangles.

Next steps

The GUESS method isn’t perfect, multistep calculations may involve multi-GUESS methods but it is a strong tool in the armoury. The next step on my Independent Enquiry journey is to embed the GUESS method at KS3, with the support of Leader of KS3 Science. Introducing the method into some lessons and end of unit assessments, with the aim to increase pupils’ confidence when attempting equation problems and hopefully ending the use of the formula triangle…

Further Reading/ References:

1. https://umanitoba.ca/student/academiclearning/media/GUESS-Chemistry.pdf

2. https://www.youtube.com/watch?v=q2oEb-tvPCM

3. https://www.smcisd.net/cms/lib/TX02215324/Centricity/Domain/1073/group%20solve%20problems%20energy%20guess%20method%202018.pdf

4. http://newtonlawofmotion.blogspot.com/2013/02/using-guess-method-to-solve-physics.html

5. https://physicsteacher.blog/2019/10/27/fifa-for-the-gcse-physics-calculation-win/

6. http://eprints.hud.ac.uk/id/eprint/29803/1/SSR%20March%202016%20049-053%20Southall.pdf

7. file:///H:/Downloads/Language%20of%20Mathematics%20in%20Science%20-%20Teaching%20Approaches%20(ASE%202016).pdf

8. (The Language of Mathematics in Science- A Guide for Teachers of 11–16 Science ASE, pg 99)