Marble chips react with excess dilute hydrochloric acid. Which change makes the reaction faster but does NOT change the total volume of carbon dioxide made?
Cambridge International and OCR · IGCSE · O Level · AS · A Level · GCSE
Now you can guarantee a win.
18 AI subject tutors, original questions set above exam standard, a practical simulator and a growing solved topical bank.
No card · 10 free tutor prompts when tutor chat opens
Start freeTry one question. No sign-up.
Pick an answer to see how a tutor explains it.
18 subject tutorsBeing updated
A named tutor for every Cambridge International subject, answering in mark-scheme style.
Above-Board questionsBeing updated
Original questions set a level above the real paper.
Forecast papersBeing updated
A predicted paper per subject, scored publicly after each series.
Practical simulatorBeing updated
Virtual practicals for Paper 6 and Alternative to Practical.
Solved topical bankBeing updated
Past-paper questions by topic, each with a worked solution.
ProPie and HackPie notesBeing updated
Free notes, plus 3D models and examiner's traps.
MCQ solverBeing updated
Timed or untimed, with the reason behind every wrong option.
Exam HallBeing updated
Sit a full paper on screen and get it marked against the scheme.
Why practise harder
Recent STEM papers have felt harder. Practise like it.
Cambridge's recent Maths and Science papers have felt tougher, and grade thresholds have moved with them.
It is a pattern that tends to repeat. Question banks are not endless, so as familiar question styles get used up, papers reach for new angles on the same syllabus.
Grade thresholds are set after marking, so a harder paper lowers the boundary. The marks still go to students who stay calm on questions they have never seen. That is exactly what our Above-Board questions train.
Why ConceptCIE
Three things, done properly
A tutor for every subject, questions harder than the exam and honest forecasts of what comes next. All three are being updated.
01 · Subject tutors · being updated
18 subject tutors
Each tutor sticks to one subject and answers the way a mark scheme reads: the steps, the key words, and the trap to avoid.
Student · sample question
Why is the current the same everywhere in a series circuit? Doesn't the first lamp use some up?
Mr Volt · PhysicsSample reply
Charge isn't used up anywhere. In a series circuit there is only one path, so the same amount of charge passes every point each second, and that rate is the current.
What the lamps take is energy from the charges, not the charges themselves. That's why the potential difference splits between them while the current stays the same.
Exam tip: Never write “current is used up”. It loses the mark every time.
02 · Above-Board questions · being updated
Set a level above the board
Being updated: original Cambridge-style questions written harder than the real paper. If you can do these, the exam feels easier. The pair below is a sample.
Solve 2x² − 7x + 3 = 0.
Show the worked answer
(2x − 1)(x − 3) = 0, so x = ½ or x = 3.
The equation 2x² − 7x + k = 0 has two different real roots, and both roots are positive. Find the set of possible values of k.
Show the worked answer
Two different real roots: 49 − 8k > 0, so k < 49/8. Both positive: the product of the roots, k/2, is positive and their sum, 7/2, is already positive, so k > 0. Answer: 0 < k < 49/8.
Why the twin is harder: The twin turns “solve it” into “reason about it”: you need the discriminant and the sum and product of roots together.
03 · Forecast papers · being updated
Revise what is likely to come up
Being updated: predicted papers built from the syllabus, past papers and examiner reports, with the method shown. A forecast, not a leak.
Forecast paper
Samplea forecast, not a leakHow each forecast is built
- Syllabus coverage. Which learning objectives have not been examined for a while.
- Topic frequency. How often each topic has appeared across past series.
- Examiner reports. What examiners say students keep getting wrong.
Forecast Scorecard
| Series | Predicted | Appeared | Hit rate |
|---|---|---|---|
| No series scored yet. After each exam series we compare the forecast with the real paper and publish the hits and the misses. | |||
Practice
Learn, practise, predict
Topical Vault, MCQ practice, Above-Board questions, Exam Hall and Forecast papers: all being updated. See what each one will do.
The Constellation
Meet the 18 tutors
One tutor per subject, each with its own personality. Tutor chat is being updated; when it opens, ask them anything in their subject, from a definition to a full exam answer.
Islamiyat
Dr Noor
The calm lantern
Floats in, glows softly, and lights up Seerah, Quran and history notes.
- O Level · IGCSE
- A Level
Pakistan Studies
Ms Minar
The tall one
Rolls in on treads and stands tall on history, geography and key dates.
- O Level · IGCSE
Urdu
Aalim Qalam
The waving pen
Hops on its nib and inks neat essays, khulasa and tashreeh.
- O Level · IGCSE
- A Level
English Language
Ms Chatter
The talker
Never stops talking: summaries, directed writing, tone and voice.
- O Level · IGCSE
- A Level
English Literature
Dr Folio
The bookish one
Monocle on, ribbon out: reads between the lines of every set text.
- O Level · IGCSE
- A Level
Mathematics
Mr Axis
The plus-and-minus
Plus-sign eyes, π on its chest, springs for legs. Equations stay balanced.
- O Level · IGCSE
- A Level
Add. Maths · Further Maths
Dr Vektor
The drone
Hovers on twin rotors and points straight at the next step of the proof.
- O Level · IGCSE
- A Level
Physics
Mr Volt
The live wire
A Tesla-coil crown, zigzag grin and caterpillar tracks. Charged for fields and forces.
- O Level · IGCSE
- A Level
Chemistry
Ms Flask
The bubbly one
Perched on a lab tripod, fizzing over with reactions and mole maths.
- O Level · IGCSE
- A Level
Biology
Dr Lens
The microscope
One giant lens eye for cells, genetics and every tiny detail.
- O Level · IGCSE
- A Level
Computer Science
Researcher Bit
The scuttling chip
Six pin-legs, a binary grin, and logic from pseudocode to processors.
- O Level · IGCSE
- A Level
Economics
Ms Graphy
The retro TV
Rabbit-ear antennas, a trend-line smile and a coin in hand. Plots where the curve goes next.
- O Level · IGCSE
- A Level
Accounting
Uncle Tally
The receipt printer
Prints a receipt for every sum and balances ledgers to the last decimal.
- O Level · IGCSE
- A Level
Business Studies
Fortune 500 Pitch
The deal-maker
Briefcase body, sharp tie, knowing smirk. Talks marketing, finance and case studies.
- O Level · IGCSE
- A Level
Geography
Mr Globo
The spinning globe
Ring-mounted and compass-crowned. Maps, climates and fieldwork skills.
- O Level · IGCSE
- A Level
History
Mr Tick
The timekeeper
An hourglass carrying a scroll. Turns back the clock on every source question.
- O Level · IGCSE
- A Level
Sociology
Team Trio
The little crowd
Three bots, hands linked. Groups, institutions and how society fits together.
- O Level · IGCSE
- A Level
Psychology
Ms Cortex
The hypnotist
A glass-domed mind with spiral eyes. Core studies and research methods.
- A Level
Notes · being updated
Two kinds of notes
ProPie explains the topic. HackPie wins the marks. Read a sample topic side by side.
Pricing
Start free. Upgrade when it counts.
Free to start, no card. Paid plans for one subject or all subjects, monthly, for the exam season or yearly, are being updated.
For parents
Your parents pay? Show them their page.
What you get, what it costs and how paying will work, written for the person paying.
Try one question. Then decide.
No card · 10 free tutor prompts to ask any of the subject tutors when tutor chat opens. Tutor chat, notes and practice papers are being updated.