7 Common OMPT Mistakes That Cost Real Points (and How to Avoid Them)

Most students who fail the OMPT do not fail on mathematics. They fail on the mechanics of the exam: how an answer has to be typed, how the clock is split across the questions, and what their programme actually demands before it accepts a score. Below are the seven mistakes that come up most often, each with the rule or number that removes it. Examify is an independent preparation site and is not affiliated with the OMPT, SOWISO or any university.

The seven mistakes at a glance

1. A correct answer in a form the checker cannot read

Answers on the OMPT are checked by a computer-algebra system (Maxima) and then reviewed by a mathematician. Do not count on partial credit for a wrong final answer. What the checker needs is an answer that is mathematically correct and unambiguous. A slip in form does not automatically cost the point, but it takes the question out of a clean automatic match and puts it in front of a reviewer, and if the entry reads as a different number, it is simply wrong.

Worked example. You solve 2x − 3 = 0 and get x = 3/2. Three entries look the same on paper: 3/2, 1.5 and 1,5. The fraction 3/2 is the safe entry: it is exact, it is what an algebra system expects, and it cannot be misread. 1.5 is the same number, but decimals are only safe when the value terminates, so for x = 4/3 a rounded 1.33 would be marked wrong. 1,5 with a comma is not a number to the checker at all, because the comma acts as a list separator in most input fields.

Before you submit, check four things: the answer is simplified (6/4 becomes 3/2, √8 becomes 2√2), it uses the variable name in the question (t, not x, if the question is written in t), it is exact rather than rounded unless the question asks for a decimal, and any decimal uses a dot. The answer-input guide walks through the editor's fraction, root and power keys one by one.

2. Never practising with the editor, the calculator or the paper rules

The exam runs in a browser with its own equation editor and a built-in calculator; your own calculator is not allowed. The test rules permit 3 A4 sheets of scrap paper, 3 pencils and one eraser, no pens, and the proctor has you tear up the sheets after submission. Students who meet these tools for the first time on exam day lose the first ten minutes learning where the fraction key is.

Fix: at least one full-length mock in the real input format, with three sheets of paper on the desk and the on-screen calculator instead of your phone. Read the proctoring rules once, a week before the exam, so the ID check and the room scan are not a surprise.

3. Using a paid attempt as a diagnostic

An official attempt costs €240 for OMPT-A, B, C, E and G, and €270 for OMPT-D and F. Every attempt is bought separately, results arrive within 8 business days, and a slot has to be booked at least 72 hours ahead. Sitting the real exam "to see where I stand" therefore costs money, a week of waiting and, for programmes that count only the first attempt, possibly the admission itself.

A full-length mock gives you the same information for a fraction of the price and without using up an attempt. Examify's paid mock has the same question count and time limit as the real module, from €39.99, with a worked solution for every question. Before that, the free OMPT practice test shows the format: two of the harder generation-1 questions per module, answered in the real on-screen input, with the worked solution after each answer. To judge how close a mock sits to the real paper, read mock vs real exam difficulty.

4. Ignoring statistics and probability in OMPT-E

OMPT-E has 161 topics in 12 chapters. Chapters 8 to 12 (descriptive statistics, probability, combinatorics, random variables, common probability distributions) hold 41 of them, about a quarter of the syllabus. Students who prepare from OMPT-A material cover chapters 1 to 7 well and walk into the exam with a quarter of the material unseen.

If your programme asks for OMPT-E, work through the OMPT-E syllabus chapter by chapter and give the statistics block its own week. The official topic list is on omptest.org.

5. Misjudging time per question

The modules differ far more in pace than students expect. OMPT-A gives 2.3 minutes per question; OMPT-D and OMPT-F give 8.6, because their questions are multi-step. Practising OMPT-D at OMPT-A speed produces rushed, half-simplified answers; practising OMPT-A at OMPT-D speed leaves a third of the paper blank.

Set one checkpoint: in OMPT-A you should be past question 26 at the 60-minute mark, in OMPT-E past question 20. If a question has taken twice your module's average, enter your best answer and move on. A wrong answer costs only that point, an empty one costs the same.

6 and 7. Booking without the programme rule, studying without the syllabus

Two rules decide whether your attempt counts, and both sit on the programme page, not on the OMPT site. The first is the minimum score: 70% on OMPT-A is common, but Erasmus School of Economics asks more than 75% on OMPT-D for Econometrics, and Rotterdam School of Management asks 75% on OMPT-A or OMPT-F. The second is the attempt limit: most programmes allow up to 3 attempts, Tilburg University allows 2, and Erasmus School of Economics counts only the first attempt for IBEB and Econometrics. If the programme page states neither, the rule is not published, so ask admissions before you book. The university list collects module, score and attempt rule per programme with a link to the source.

The related mistake is treating the OMPT as a general maths test. Each module has a fixed, published topic list: 176 topics for OMPT-A, 242 for OMPT-D, 66 for OMPT-C. Anything outside that list, complex numbers for OMPT-A or matrices for OMPT-E, is time you will not get back. Study from the syllabus for your module and tick topics off it.

What prepared students actually score

The test provider publishes one figure worth remembering: students who worked through the learning materials scored on average 76% on their first attempt; students who did not scored 40%. That 36-point gap is larger than the difference between any two modules. The cheapest route from the second group to the first is a full-length mock, a pass over the seven rows above, and a study plan built from the syllabus instead of from a general textbook.