Problem J01
Number theoryShort answerSolvedHow many whole numbers from 1 to 200 have digits that add up to 5?
Everything a keen IB student needs to get started with competition maths: what the UKMT challenges, the AMC 8, AMC 10 and AMC 12 and the maths olympiads are, how to enter, links straight to the official past papers, and 120 original competition-style problems of our own with hints and full solutions.
Competition problems are a good stretch alongside IB Maths: they reward the reasoning and proof skills that Paper 3 and the internal assessment reward, and they are a common enrichment choice for students aiming at a 7 or at university maths.
Links only We link to the organisers’ official past papers; we don’t host them, and our practice problems are our own, not copies.
A new problem every Monday, rotating through all three levels.
How many whole numbers from 1 to 200 have digits that add up to 5?
Forty problems at each level, in six topics. Choose the level for your age, then filter by topic.
Same age band as the UKMT Junior Mathematical Challenge and the MAA AMC 8.
Short problems that need careful thinking rather than advanced content: counting, digits, angles, simple equations and logic puzzles.
40 problems →Same age band as the UKMT Intermediate Mathematical Challenge and the MAA AMC 10.
GCSE / IGCSE / Class 9–10 content used in unfamiliar ways: modular arithmetic, clever counting, circle and area geometry, conditional probability.
40 problems →Same age band as the UKMT Senior Mathematical Challenge and the MAA AMC 12.
A Level / IB / Class 11–12 ideas: recurrences, inclusion–exclusion, Vieta, expectation, 3D geometry and harder logic.
40 problems →Each link goes to the organiser’s own website. We don’t host their papers, and details such as dates and prices change every year, so check there.
UK
Three individual Challenges sat in school: Junior (Year 8 and below, England and Wales), Intermediate (Year 11 and below) and Senior (Year 13 and below). Each first round is 25 multiple-choice questions; the Junior and Intermediate papers last 60 minutes and the Senior 90 minutes. High scorers are invited to follow-on rounds: Kangaroo papers and Olympiads with written solutions. Schools enter their students; there is no individual entry.
How to enter: Ask your maths teacher or exams officer: schools register and buy entries through UKMT.
USA and international schools
Run by the Mathematical Association of America. The AMC 8 (grade 8 and below) has 25 multiple-choice questions in 40 minutes. The AMC 10 (grade 10 and below) and AMC 12 (grade 12 and below) each have 25 multiple-choice questions in 75 minutes. Top AMC 10/12 scorers are invited to the AIME and then the USA olympiads. Students take the AMC at a registered school or competition site.
How to enter: A teacher or competition manager registers the school with the MAA; students then sit the paper there.
Australia, New Zealand and other schools
The Australian Maths Trust runs the Australian Mathematics Competition for school years 3 to 12: 25 multiple-choice questions followed by 5 integer-answer questions, in 75 minutes for secondary papers. Past papers are sold through the AMT shop.
How to enter: Schools register with the Australian Maths Trust; students enter through their school.
India
The Homi Bhabha Centre for Science Education runs India’s Mathematical Olympiad programme. The first stage is the Indian Olympiad Qualifier in Mathematics (IOQM), with integer-answer questions; it leads to the Regional and Indian National Mathematical Olympiads. HBCSE publishes past papers and solutions.
How to enter: Registration opens each year on the official Olympiad site, usually through a registered centre or school.
Use the problems for a stretch starter, an enrichment club or extension homework. On any problem page, open ‘For teachers’, switch on ‘Add to worksheet’ and pick problems: they go into the same worksheet basket as our question bank, so you can print them from the worksheet builder or set them as homework for a class, with the full solutions as the mark scheme. They are free for every class, including free teacher classes.
On the UK Mathematics Trust’s own website: its competition papers page has free past papers for the Junior, Intermediate and Senior Mathematical Challenges, with solutions, and older papers are sold in the UKMT shop. We link to those pages above. We don’t host UKMT papers or copy their questions.
The Mathematical Association of America publishes sample competitions and sells past AMC papers; its AMC pages are linked above. For extra practice in the same spirit, our 120 original problems are grouped by the same age bands: Junior (AMC 8 age), Intermediate (AMC 10 age) and Senior (AMC 12 age).
No. Every problem in this section was written by us and is labelled competition-style. None is taken from, or reworded from, a UKMT, MAA AMC, Australian Mathematics Competition or IOQM paper, and each answer is checked independently by a computer program.
Almost always through their school: UKMT, the MAA and the Australian Maths Trust sell entries to schools, and students sit the paper there. Ask your maths teacher or exams officer. India’s IOQM has its own registration each year on the HBCSE Olympiad site.
Start at the level for your age: Junior for ages 11 to 13, Intermediate for 13 to 16 and Senior for 16 to 18. IB students usually start at Senior. If the first few feel easy, move up a level.
Yes. On any problem page open ‘For teachers’, switch on the ‘Add to worksheet’ buttons and pick problems. They go into your worksheet basket, so you can print them from the worksheet builder or set them as homework, with the solutions as the mark scheme. They are free for every class.