ChatGPT can tutor a Cambridge Lower Secondary student well if a parent writes clear instructions and checks the answers. A dedicated AI tutor such as CoreMark Coach adds a fixed structure: Stage 9 scope, Learn and Exam modes, method-mark marking and weak-topic tracking. If you enjoy setting that up yourself, ChatGPT may be all you need.
CoreMark makes CoreMark Coach, one of the two options compared here, so read this as a maker's honest view. ChatGPT is made by OpenAI, and CoreMark has no connection to it.
Most parents we hear from have already tried ChatGPT with their child. Some are delighted, some found the answers wandered off syllabus, and a few are simply wondering whether paying for anything else is silly. This guide sets out what each option does, where ChatGPT is the better choice, and a ten-minute test you can run yourself before spending anything.
What does ChatGPT's Study mode actually do?
Study mode is a ChatGPT setting that asks questions first and works toward an answer step by step, instead of handing the answer over straight away. OpenAI's help centre describes it as a learning experience that "asks interactive questions to understand your goals and skill level". Per that page, it launched for Free, Plus, Pro and Team users and works on web, iOS and Android.
You switch it on for each chat (typing @study or choosing Study from the tools menu). OpenAI also states two limits worth knowing: it can make mistakes, and in some cases it will still give a direct answer. The same page says Study is not available inside Projects, GPTs or Temporary Chats, which means you cannot pair it with a Project that holds your own syllabus notes. Details are in OpenAI's help article, and it is worth rereading before you rely on it because features change.
What does a parent have to supply when using ChatGPT alone?
A parent has to supply the tutoring brief. ChatGPT knows a great deal, but nothing in it says "this child is in Cambridge Lower Secondary Stage 9, so stay inside that curriculum, and do not drift into IGCSE content". You write that, and you decide the rest as well:
- how questions are asked (one at a time, or five at once);
- whether it may give hints during a practice paper;
- how a wrong answer is marked, including whether method marks count;
- whether it should come back to a weak topic later, and how it will know which one;
- what tone is right for a 13 year old who has just got three questions wrong.
Plenty of parents enjoy this and get good results. It is also real work, and it has to be repeated whenever the setup changes. The brief and the checking are the price of the lower cost.
Which tutoring jobs does each option handle?
The table lists the jobs a tutor has to do for a Stage 9 student. Under ChatGPT we describe what is possible with good prompting from you; under Coach we describe what is built into the Coach file. Neither column promises correct answers.
| Job | ChatGPT, with your prompting | CoreMark Coach |
|---|---|---|
| Stay inside Stage 9 | Only if your instructions say so, and you check | Built around the Stage 9 curriculum; redirects other stages |
| Set an exam-style paper | Possible if you specify it each time | Topic test, practice paper or Checkpoint-style mock, one question at a time, no hints on a mock |
| Mark with method and accuracy marks | Possible if you ask for it | Marks method (M) and accuracy (A), with follow-through, after the paper is submitted |
| Name the first wrong step | Possible if you ask for it | Part of the marking report, grouped by idea |
| Bring weak topics back later | You track it, or rely on whatever memory features your account has | Designed to note weak topics and offer reviews, using Claude's memory (not guaranteed) |
| Subjects and stages | Any subject, any level | Stage 9 Maths, Science and Computing only |
| Cost | A free plan exists; paid plans cost more | ₹9,999 per stage for the school year, with ₹4,999 on offer to the first 100 families at the time of writing, plus a Claude account |
What would a good ChatGPT tutoring brief look like?
If you go the ChatGPT route, put the rules in the first message of every session. Something like this covers the jobs in the table, and you can adjust the wording for your child:
You are a patient tutor for a 13 year old studying Cambridge Lower Secondary Stage 9 Maths. Stay inside that curriculum, and if something belongs to a later qualification, tell me it is bonus knowledge. Ask one question at a time. During a practice paper, give no hints. After the paper, mark every answer with method marks and accuracy marks and tell me the first step where I went wrong. Keep explanations short, and ask me to explain each idea back in my own words before moving on.
This is a starting point, not a tested recipe: we have not measured how closely any chatbot follows it. Try it on a topic your child already knows, so you can tell whether the marking is fair. Writing, testing and reapplying a brief like this is the work a purpose-built tutor does for you, and it is a fair description of what you would be paying for.
Where is ChatGPT simply the better choice?
ChatGPT is better whenever breadth or price matters more than structure. It covers English, History, languages and every other subject, for children of any age, and a free plan exists. It is also the better pick for a family with several children at different levels, because one account and a few good prompts cover everyone. Coach covers one stage of three subjects and nothing else.
Another difference is who can hold the account. OpenAI's Terms of Use require users to be at least 13 (or the minimum age in their country), with a parent or guardian's permission for anyone under 18. Anthropic, which makes Claude, requires every account holder to be at least 18, according to its help centre. That is why Coach runs from a parent's Claude account, and why a teenager cannot simply sign up alone.
Does a dedicated tutor mean you can stop checking the answers?
No. Every AI tutor can be wrong, ChatGPT and Coach included. OpenAI says so about Study mode, and Coach's own guidance says no AI is perfect. Coach is built to check each question, work out each answer independently before marking a student wrong, and run its diagrams through a checklist. That lowers the odds of a slip but does not remove them.
How can you test both for free in ten minutes?
Run the same short test on any tool you are considering and judge the results yourself. Pick one Stage 9 topic your child finds hard, such as angles in parallel lines or the reactivity series, and work through this list:
- Ask for five practice questions. Does any need content from a later qualification?
- Answer two of them badly on purpose. Does the tool find the first wrong step, or only say "incorrect"?
- Ask for a full paper under exam conditions. Does it give hints you did not ask for?
- Ask a question the topic does not need, such as a different subject. Does it stay on task?
- Come back tomorrow in a new chat. Does it know which topic went badly?
- Time how long it took you to set up. Would you do that every week?
The last two lines usually decide the question. Families who do not mind setting things up are well served by ChatGPT. Families who want to type "hi" and start tend to value a ready-made structure.
Who should just use ChatGPT, and who should pay for Coach?
Use ChatGPT if you have the time to write and maintain instructions, your child needs help across many subjects, or the budget is zero. Consider Coach if your child is in Stage 9 and needs Maths, Science or Computing help, you would rather not write the tutoring brief yourself, and you are comfortable running a Claude account as the adult. If neither feels right, the PDF boosters are a much cheaper way to get structured practice on paper.
ChatGPT is the sensible default for most families to try first. A dedicated tutor earns its price only when the structure it supplies is something you would otherwise spend your own evenings building. Details on what is inside are on the Coach page.
See how Coach works
CoreMark Coach is an AI tutor for Cambridge Lower Secondary Stage 9 that runs in Claude.
Frequently asked questions
Yes, with good instructions and checking. ChatGPT is capable across subjects, but it will not stay inside the Stage 9 syllabus unless you tell it to, and it can make mistakes. Write a brief naming Cambridge Lower Secondary Stage 9, test it on a topic your child knows, and compare answers with a worked solution.
According to OpenAI's help centre, Study mode launched for Free, Plus, Pro and Team users, so it is not limited to paid plans. Plans and limits change, so check OpenAI's current help article before you rely on it. Study mode is switched on for each chat rather than being a permanent setting.
No. CoreMark Coach is made for Claude only and does not work in ChatGPT, Gemini, Copilot or other AI apps. It runs as a file you add to a Claude Project, from a parent's Claude account, and covers Cambridge Lower Secondary Stage 9 Maths, Science and Computing.
OpenAI's Terms of Use say users must be at least 13, or the minimum age in their country, and that anyone under 18 needs a parent or guardian's permission. Rules and parental controls change, so read OpenAI's current terms. Claude's account rules differ: Anthropic requires account holders to be at least 18.
We have not run a head-to-head accuracy test, so we will not claim one is better. Both can make mistakes on school maths, and both companies say so. Whichever you use, check a sample of answers against a worked solution each week and ask the AI to show its working when something looks wrong.
Coach is written and tested for Claude, including the way it uses Claude Projects, memory and diagram creation. CoreMark does not support it anywhere else, and we cannot say how it would behave in another app. If you want a ChatGPT setup, you would be writing your own tutoring brief.
Sources & further reading
- OpenAI, "Using study mode in ChatGPT", help centre, help.openai.com
- OpenAI, Terms of Use, openai.com
- Anthropic, "Minimum age requirement", Claude help centre, support.claude.com
- Anthropic, "What are projects?", Claude help centre, support.claude.com
Last updated 20 October 2026. Details about other companies and research were checked against their own pages on 20 October 2026; check current terms, features and prices before you decide.
CoreMark Coach is an independent product that runs in Claude, made by Anthropic. CoreMark is not affiliated with Anthropic or with Cambridge Assessment International Education. AI can make mistakes: check important answers, and supervise your child's use.