Four things we changed about how we teach — this term

Most centres will tell you their teaching is good. Very few will tell you what went wrong in a lesson last month and what they did about it. We keep a written teaching diary for exactly that: the observation, the diagnosis, and the change made to the notes, the slides or the practice. It is not a marketing document — it is a working file, and it is the main reason our materials are different this term from last.

Here are four entries from one term of Secondary 3 Pure Chemistry, translated out of our internal shorthand. They are small, specific and unglamorous, which is rather the point.

1. We started from what students could not do, not what they had not covered

A class had finished a full round of mixed practice papers and could answer the questions. Asked to explain their answers, they could not. In Chinese there is a phrase for this — 一知半解, knowing half of it — and it describes the state precisely: the marks were there, the understanding was not.

Two symptoms kept appearing. In Redox, students could not say which of a metal and a non-metal was oxidised and which reduced. In the Periodic Table, they could recite that Group 1 metals are soft, melt at low temperatures, conduct electricity and react with water — four separate memorised facts, with no model underneath connecting them.

The diagnosis was that neither problem lived where it appeared. Both traced back to Chemical Bonding, and specifically to two ideas that had never properly landed: what a metal actually is at the particle level, and why metals lose electrons while non-metals gain them. Fix those two and all five symptoms resolve at once. Drill the symptoms instead and you are treating a rash.

Why working backwards matters

Most practice questions run in the same direction the notes taught in. But knowing that 1 + 1 = 2 is not the same as knowing what 2 − 1 is, or what fills the blank in 1 + ? = 2 — and a student who has only ever gone forwards will freeze the first time an exam runs the relationship the other way. Every set we build now includes at least one question that runs backwards and one with a missing middle, before it asks the student to transfer the idea anywhere new.

2. We re-ordered a whole chapter so one thing could be derived instead of memorised

Acids, Bases and Salts is usually taught with pH early. We now teach strong versus weak acids first, and only then pH — and we frame pH as the concentration of hydrogen ions rather than a number on a chart.

That ordering does real work. It lets pH follow from two things a student already understands: how concentrated the acid is, and how readily it splits up in water. Taught in that order, the classic exam discriminator — two acids at the same concentration with different pH — is not a trick to be memorised. It is the only thing that could have happened.

The same entry pushed the chapter's properties section to reach back to Bonding explicitly. Acids and bases behave as they do because of what their particles are, and a student who has just spent a fortnight on bonding should be made to use it rather than start again.

3. One picture replaced three tables

The reactivity series is normally taught as a stack of tables: metals with cold water, metals with steam, metals with dilute acid. A teacher's handwritten board notes did it differently — one vertical list of the metals, with an arrow beside it for each reaction showing exactly how far down the list that reaction still works. Cold water stops after calcium. Steam carries on to iron. Dilute acid stops at hydrogen.

That single chart answers every “does this metal react with that?” question a student will ever be asked, and it does it visually, in one glance. Three tables cannot do that, because the answer lives in the comparison between them.

The draft materials had the tables and not the arrows. The arrows were the load-bearing part.

4. When a lesson was doing two jobs, we split it

The reactivity series had been folded into a larger Periodic Table and Metals unit. Reviewed as a finished deck, it was clear that the reactivity arc — reactions with water, steam and acid, then extracting metals from their oxides, then displacement and rusting, then carbonates — is a complete lesson in its own right. Buried inside a fifty-slide unit, it was being diluted by everything around it.

So we split one topic into three, and put them in the order the ideas actually depend on each other: redox, then the Periodic Table, then the reactivity series, then metals. More topics is more work. It is also the right shape.

Why we bother writing any of this down

A teacher who notices something in class on a Tuesday and fixes it privately has improved one lesson. Written down, examined for its root cause and pushed back into the materials, the same observation improves every class that comes after — including the ones taught by someone else.

• We log wrong answers by question, not by topic. “Weak on bonding” is not actionable. “Seven students out of twelve missed the same inverse question” is.
• We look for the root, not the symptom. Five complaints that turn out to be two causes is the normal result, and it saves everyone a great deal of drilling.
• We rebuild materials that are already drafted. The re-sequenced chapter above had finished notes and slides. They were wrong in order, so they were rebuilt.
• We write down what we do not know yet. The diary has an open-questions section. Some of those questions have been sitting there for weeks.

Improving how we teach is part of the job, not something a teacher is expected to do in their own time.

None of this is visible from outside a classroom, which is why we are writing it here. If you are choosing between centres, it is a fair question to ask any of them: what did you change about how you teach this term, and what made you change it?