Are You a Believer or a Non-Believer?

By Michael Camp

Secondary Mathematics Teacher

A few years ago, when X was Twitter and had a lovely blue bird logo, the following meme caused many arguments and possibly a disproportionate amount of online anger.

Are you a believer… or a non-believer?

Some people start by subtracting: 230 minus 220 to get 10. Then, 10 multiplied by 0.5 equals 5. Believer status confirmed.

But if that’s you, maybe you’ve forgotten that in maths, multiplication comes before subtraction (BIDMAS/BODMAS/PEMDAS*). If you remember the correct order, you first multiply 220 × 0.5 = 110, then subtract to get 230 – 110 = 120.

Now here’s the twist: even though 120 is the correct result of the arithmetic, the meme is correct. If you are a non-believer, you have either missed something carelessly or you may be ignorant of the mathematical explanation.

In mathematics, 5! (read as "five factorial" not ‘FIVE’ in a loud voice) is 5 × 4 × 3 × 2 × 1 = 120. It can be used to find the number of ways you can arrange 5 objects. The joke hinges on interpretation. The answer isn’t 5 — it is 5!.

And that brings us to what we see time and time again in student assessments.

When our students review their assessments, mistakes fall into three categories:

1. Careless – typos, skipped steps, or misreading the question (like the maths experts who missed the !).
2. Forgetting – they could do the maths in class but not when asked later (like those who believed the answer was 5).
3. Ignorance – they never fully understood the topic or method to begin with (like the disbelievers who knew the answer was 120 but has never heard of factorials).

If every student forgot the same thing or misunderstood the same method, it might suggest something we need to address in our teaching. But usually, each student has their own unique mix of gaps and misconceptions — individual stepping stones missed, forgotten, or mis learned.

Just because a student can do something once in class doesn’t mean they’ve mastered it. Mastery is a process of learning, practicing, forgetting, reviewing, and finally owning that knowledge.

How We're Addressing This in Grades 6-10

To help address this, all our MYP students now have accounts with Complete Maths Tutor  (completemathstutor.com), an adaptive online platform that personalises homework based on each student’s learning profile. It identifies knowledge gaps, recommends personal goals, and ensures that practice is meaningful, focused, and just right for the individual.

Each week, students are expected to complete at least six personal goals: their “Focus 5,” plus tasks linked to their weekly review quiz. A daily “memory boost” is also available to reinforce key ideas. These are manageable expectations — one student even completed 56 goals in a single week (a little excessive, but impressive nonetheless!).

If goals routinely seem “too easy,” students are encouraged to retake the diagnostic. Occasional easy goals often indicate a subtle weakness in something the student thought they’d mastered. To achieve a goal a student must score 100% on a quiz to confirm they are ready to move on.

From now on, when homework isn’t completed, we’ll be contacting home — and students will be asked to reflect: Why didn’t I do it? How has this affected me? What’s my plan moving forward? Parents can support this process by setting up a free Complete Maths account to track progress and support their child, we can assist any parents who wish to set up their own account.

Progress is not about tricks or shortcuts. It’s about depth, understanding, and building mathematical fluency that lasts. And yes — we all make silly mistakes. I certainly still do. But with practice, students become more aware of what’s reasonable (can a fish really be –3.4 cm long?), they are more confident in their abilities, and much less prone to careless calculator errors.

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* I personally have an issue with BODMAS/BIDMAS and PEMDAS as they all incorrectly imply division is done before multiplication and addition before subtraction but that is a topic for another day.