For each subtopic, students are given a set of resources that work together.

A typical subtopic includes:

• a theory video;
• an application video;
• a practice worksheet;
• detailed written worksheet solutions.

For each larger topic, students also receive:

• a topic cheat sheet or summary resource.

Over time, Catalyst will continue expanding its resource library. Planned additions include worksheet video walkthroughs, practice tests, practice exams, solutions for practice assessments, past exam video walkthroughs, and dedicated videos on exam preparation and technique.

But even from the beginning, the goal is simple: every piece of content should have a purpose.

The theory videos teach the content.
The application videos show how to use it.
The worksheets give students a chance to practise it.
The solutions help students check and correct their work.
The cheat sheets summarise what matters.

Theory Videos

Theory videos are the main teaching videos on Catalyst.

These are designed to feel like a structured lesson with a teacher or tutor who is sitting down and walking students through the content properly.

The purpose of a theory video is not just to say, “Here is the rule, memorise it, good luck.” That approach is rarely enough, especially in senior STEM subjects where students are often expected to apply concepts in unfamiliar situations.

Instead, Catalyst theory videos aim to build the ideas from the ground up.

Depending on the subject and topic, a theory video may include:

• the main background information for the lesson;
• key definitions and terminology;
• important formulas, laws, rules or theorems;
• explanations of where major ideas come from;
• derivations or intuitive reasoning behind formulas where appropriate;
• links to real-world applications;
• diagrams, examples or visual explanations;
• key warnings about common misunderstandings;
• a clear summary of the most important takeaways.

Each theory video begins with learning intentions, so students know exactly what the lesson is going to cover before they start.

This is especially useful because senior subjects can get overwhelming very quickly. Students are often thrown a lot of information at once, and it can be hard to know which parts are genuinely important and which parts are just background detail.

The learning intentions help set the map before the lesson begins.

At the end of each theory video, students are also given a summary of the key points from that lesson. This gives them a quick way to check that they understood the main ideas before moving on.

For mathematics subjects, theory videos also include at least one worked example question at the end of the video. This gives students a chance to see the theory in action before they move into the heavier application questions.

For science subjects, most worked examples are saved for the application videos, so the theory videos can focus more on concepts, processes, terminology and understanding.

The big idea is that students should walk away from a theory video feeling like the topic makes more sense than it did before.

Not necessarily perfect. Not necessarily “I am now the chosen one of calculus.” But clearer, calmer and more ready to practise.

Application Videos

Application videos are where students see the content being used in actual questions.

These videos focus on test-style, exam-style and higher-application questions that connect directly to the subtopic.

This is where students get to see how a subject expert thinks through a question from start to finish.

An application video does not just show the answer. It breaks down the process.

That includes:

• reading the question carefully;
• identifying what the question is asking;
• choosing the right method or formula;
• setting out working clearly;
• explaining why each step is being done;
• pointing out common traps;
• showing how marks may be earned;
• discussing what a strong response should include;
• building confidence with different question types.

These videos are especially important because many students can understand the theory when it is explained to them, but then get stuck when the question changes slightly.

That is very normal.

A student might know the formula, understand the concept, and still look at an exam-style question and think, “Absolutely not. This question is speaking a different language.”

Application videos are designed to bridge that gap.

They show students how to move from knowing the content to actually using the content.

By the end of an application video, the goal is for students to feel more comfortable with the types of questions they might face in school tests, assignments, practice tasks and exams.

Students can use these videos in two main ways.

If they are feeling confident, they can pause the video, attempt the question first, and then watch the walkthrough to compare their thinking.

If they are not feeling confident yet, they can watch the expert walkthrough first, learn the approach, and then try a similar question afterwards.

Both methods are valid. The main thing is that students are actively engaging with the problem-solving process, not just watching someone else do all the thinking.

Because sadly, no matter how much we may all wish otherwise, you cannot absorb Specialist Mathematics through vibes alone.

Practice Worksheets

Every subtopic on Catalyst comes with a custom practice worksheet.

These worksheets are designed to give students targeted practice on the specific lesson they have just completed.

In a way, the worksheets act like homework or textbook-style practice, but with a more focused Catalyst structure. They give students the chance to test whether they can actually apply what they have learned, rather than just feeling like they understood the video.

Because that is a very real trap.

Watching someone explain something and thinking, “Yep, that makes sense,” is not the same as being able to do it yourself under test conditions.

The worksheets are designed to help close that gap.

Each worksheet includes a range of question types based on the subtopic. Depending on the subject and lesson, this may include:

• routine skill-based questions;
• short-answer questions;
• calculation-based questions;
• application questions;
• interpretation questions;
• exam-style questions;
• extended reasoning questions;
• multi-part problems.

The questions are designed to feel relevant to what students are likely to see at school. They are structured around the kinds of skills, concepts and question styles students encounter in their textbooks, topic tests and senior assessments.

Each worksheet also includes an information page near the beginning that outlines:

• what the worksheet is testing;
• the general skills involved;
• the total marks available;
• the recommended completion time;
• how students should approach the worksheet.

This helps students treat the worksheet as more than just “extra questions”. It gives the task a bit of structure, almost like a mini test or targeted revision activity.

Students are encouraged to attempt the worksheet properly before looking at the solutions. That means setting aside time, writing out working clearly, and treating mistakes as useful feedback rather than a personal attack from the universe.

At the end of the worksheet, students also have a reflection page where they can record their score, identify what went well, and note what they need to revise.

That reflection step is important.

The goal is not just to finish the worksheet. The goal is to learn from it.

Written Worksheet Solutions

Catalyst worksheets come with detailed written solutions.

These solutions are designed to help students check their work, correct mistakes and understand the reasoning behind each answer.

In many subjects, especially maths and science, the final answer is only one part of the process. Students also need to understand:

• which method was used;
• why that method was chosen;
• how the working was structured;
• where marks may be awarded;
• what assumptions were made;
• how units, notation or terminology should be handled;
• where errors commonly occur.

The written solutions are designed to model that process clearly.

Students should use the solutions after they have attempted the worksheet themselves. This gives them a much better sense of what they actually understand and what they still need to revise.

A good way to use the written solutions is:

1. Attempt the worksheet without help.
2. Mark each question using the solutions.
3. Identify where marks were lost.
4. Rework any questions that were incorrect or incomplete.
5. Record the score and reflection on the worksheet reflection page.
6. Revisit the theory or application video if needed.

This process helps students move from simply “doing questions” to actually improving.

Because improvement does not usually come from getting everything right the first time. It comes from finding the mistakes, understanding why they happened, and fixing them properly.

Annoying? Yes. Effective? Also yes.

Topic Cheat Sheets

Catalyst also provides cheat sheets for each major topic.

These are not created for every individual subtopic. Instead, they are designed to summarise the key information from a full topic.

For example, a topic cheat sheet might cover an entire area such as Quadratics, Trigonometry, Differential Calculus, Organic Chemistry or Homeostasis.

The purpose of a topic cheat sheet is to give students a clean, condensed summary of the most important ideas.

Depending on the subject and topic, this may include:

• key formulas;
• important definitions;
• rules and laws;
• diagrams;
• processes;
• common question types;
• important methods;
• common mistakes;
• test tips;
• summary notes.

These cheat sheets can be used in two main ways.

First, they can be used as a quick revision tool. Before a topic test, students can read through the cheat sheet to remind themselves of the key ideas they need to know.

Second, they can be used as a model for students who are allowed to create their own summary sheet or cheat sheet for school assessments.

Many students are told they can bring a summary sheet into a test, but they are not always taught how to make one properly. They either write too much, write too little, copy random examples, or create something so chaotic that even they cannot understand it during the test.

Catalyst cheat sheets help students see what a useful topic summary can look like.

They are not designed to replace learning the content. They are designed to help students organise the content and revise it more effectively.

A good cheat sheet should make the important ideas easier to find, not act as a magical academic safety blanket.

Although, to be fair, during Year 11, we all need a safety blanket sometimes.