The ClassWiz Ratio menu: how you can make the most of it

Claire Clay, Lead Practitioner for Maths at Ormiston Academies Trust, is a big advocate for more widespread use of calculators in secondary schools.

We’ve had the opportunity to speak with Claire and share her thoughts on various topics in the past, including Casio’s ClassPad platform, and the benefits of students starting to use scientific calculators early on in key stage 3.

In this blog, we’re focusing on the uses and benefits of the Ratio menu on our entry-level fx-83GT CW and fx-85GT CW ClassWiz models. Claire has created some resources with step-by-step demonstrations showing how you can apply this functionality to ratio questions in your lessons.

A bit of background…

Ratio questions have become an increasingly common sight in GCSE maths exam papers since 2017.

Despite this, Claire has noticed a distinct lack of calculator use when exploring this topic in lessons, even though Casio’s scientific handsets offer an app dedicated entirely to ratios.

This prompted conversations within Claire’s Trust about why this is the case, and what resources could be produced to show teachers and students how calculators can enable more efficient teaching and learning.

A new resource for ratios

The starting point for the development of Claire’s calculator-focused ratio resources was this blog by her colleague Amie Meek. It looks at the various ways ratio tables can be used to present and unpack this topic throughout key stages 3 and 4.

Sub-topics covered in the blog range from FDP equivalence, multiplication and division in year 7, to using graphs and multiplicative reasoning in year 11.

Claire has developed and expanded this into a 59-page PowerPoint presentation, based on one fundamental idea: what you can do in a ratio table, you can also do in the Casio ClassWiz Ratio menu.

Using questions from Corbett Maths, the presentation gives a detailed breakdown of how you can use this functionality on the fx-83/85GT CW handsets to tackle various aspects of ratios, including:

• Finding one part of a ratio from another part
• Writing a ratio in the forms 1 : n and n : 1
• Interpreting pie charts
• Calculating unit conversions
• Solving problems using direct proportion
• Increasing and decreasing amounts by a percentage

Claire noted that encouraging and normalising calculator use through activities like these can offer all sorts of benefits, including more autonomy and understanding of the technology for students.

“To support our students as effectively as possible, we need to be using the best tools available,” she said.

“Of course, I’m never going to say we shouldn’t be teaching non-calculator methods. But there’s no reason why we can’t demonstrate the non-calculator method, then introduce students to the calculator method for them to mark their own work.

“Through doing that, they will see and learn from any mistakes they might have made, and also learn how to use that function on the calculator.”

Boosting awareness and outcomes for teachers and students

One possible reason why some teachers and students might not be using the Ratio menu on their ClassWiz calculators is a lack of awareness about how much it can do.

Claire gave the example of a recent demonstration to a colleague, where she showed him how this functionality can be applied to increasing and decreasing amounts by a percentage.

He then said he would be using the method in his very next lesson on percentages.

“It often just comes down to awareness and time,” Claire said. “As we learn more about what these calculators can do, we can upskill ourselves and consequently help our students.”

Bearing in mind that two out of the three GCSE maths papers allow calculators, students can give themselves a big advantage by building familiarity and confidence with the technology.

Claire pointed out that knowing how a calculator can help them answer questions involving ratios, fractions, decimals and percentages will be a “massive” help to the average GCSE maths student.

Delving deeper than the Ratio menu

The fx-83/85GT CW scientific calculator offers plenty of functionality beyond the Ratio menu, including a dedicated app for statistics.

This is another feature of the calculator that may go overlooked by teachers and could be used much more extensively for activities such as sorting fractions, decimals and percentages.

Claire recently visited a school that was marking its mock exams and saw lots of marks being dropped on questions involving sorting decimals.

Other good examples include showing inequalities on a number line and calculating mean and median from a table. These are all capabilities of an entry-level ClassWiz scientific calculator that can be a big help to students in exams.

“Of course, they need to show their working to get all available marks,” Claire pointed out. “And they need to know where the tools are, how to use them and how to understand the calculator’s output. But if they have that knowledge and familiarity, they’re giving themselves an advantage in exams.”

In addition to the new PowerPoint presentation, Claire has created a free library of information cards with step-by-step instructions for various tasks and operations on the fx-83/85GT CW, including:

• Ordering fractions, decimals and percentages
• Writing ratios in the forms 1 : n and n : 1
• Using the ANS and Format keys
• Finding lowest common multiples and highest common factors
• Defining and using functions in terms of f(x)

You can also keep an eye on the Casio Education blog for more insights, tips and resources from Claire in the future.