Part-66 Module 1 Mathematics Questions and Practice Paper

Part-66 Module 1 questions test the mathematics every licensed engineer uses on the hangar floor: converting units, working out percentages and ratios, rearranging a formula and reading a graph. It is usually the first module people sit and one of the shortest. This page explains how long the Module 1 paper is for each licence category under EASA and UK CAA rules, what every sub-module covers, where candidates lose marks, and how to prepare with free exam-style papers.

Part-66 Prep is an independent study aid, not an authority or a Part-147 organisation. The syllabus comes from Appendix I and the exam standard from Appendix II to Part-66 in Regulation (EU) No 1321/2014 for EASA licences, and in the retained UK Part-66 on legislation.gov.uk for UK licences. For how Module 1 fits with the other sixteen, see the Part-66 modules guide.

Part-66 Module 1 paper size by category

Every category sits Module 1, but not at the same length. All papers are three-option multiple choice with one correct answer, about 75 seconds a question and a 75% pass mark.

Category	EASA questions / time	UK CAA questions / time	Marks needed to pass
A (A1 to A4)	16 / 20 min	16 / 20 min	12
B1.1, B1.2, B1.3	32 / 40 min	32 / 40 min	24
B2	32 / 40 min	32 / 40 min	24
B2L	32 / 40 min	32 / 40 min	24
B3	32 / 40 min	28 / 35 min	24 (EASA) / 21 (UK)

So for most people the paper is the same in both systems. B3 is the exception: the retained UK Appendix II still has the shorter 28-question paper, while Regulation (EU) 2023/989 brought the EASA B3 paper up to the B1 length from 12 June 2024.

Key fact: On a 32-question paper you can drop eight marks and still pass. On the category A paper you can drop only four. Short papers punish careless slips, so accuracy matters more than speed.

How the questions are spread

EASA's acceptable means of compliance (AMC1 to Appendix II) suggests how many questions should come from each part of the syllabus. For the 32-question B paper it gives about 6 on arithmetic, 4 on simple algebraic expressions, 12 on equations, 3 on geometrical constructions, 4 on graphs and 3 on trigonometry. Category A gets about 6 on arithmetic, 5 on algebraic expressions and 5 on graphs. Exam setters may deviate from these figures, but the message is clear: for B candidates, equations are more than a third of the paper. Our timed Module 1 paper 1 for B1.1 follows this spread.

What Part-66 Module 1 mathematics covers

The syllabus has three sub-modules. Knowledge levels come from Appendix I: level 1 means familiarisation with the main elements, level 2 means a general working knowledge you can apply, level 3 means detailed knowledge. Category A works at level 1 on most of Module 1; B1, B2, B2L and B3 work at level 2 on most topics and level 1 on equations and constructions. Our free Module 1 arithmetic note sets out the levels in full.

1.1 Arithmetic

This is the base for every calculation in later modules. Expect:

• arithmetical terms and signs, order of operations
• multiplying and dividing fractions and decimals, converting between them
• factors and multiples, highest common factor and lowest common multiple
• weights, measures and conversion factors between units
• ratio and proportion, averages and percentages
• areas and volumes of simple shapes, squares, cubes, square roots and cube roots

Examiners like questions that look trivial but contain one trap: a unit that has to be converted first, a percentage of a percentage, or a ratio given the other way round. Appendix II says the wrong options in numerical questions must come from procedural errors, such as a correction applied in the wrong sense or a wrong unit conversion. In practice the most common mistake is always one of the three options.

Exam tip: Before you calculate, write the units next to every number. If the question gives millimetres and asks for metres, the answer you get by forgetting to convert will be sitting there as option A.

1.2 Algebra

Algebra is the heaviest part of the B paper. The syllabus splits it into:

• (a) Simple algebraic expressions: evaluating expressions, adding, subtracting, multiplying and dividing terms, brackets, simple fractions in algebra.
• (b) Equations (B only): linear equations and their solutions, simultaneous equations and second-degree equations with one unknown, indices and powers (including negative and fractional indices), binary and other numbering systems, and logarithms.

The things that cost marks are sign errors when moving a term across the equals sign, forgetting that a negative index means a reciprocal, and mixing up the rules for multiplying and dividing powers. Number systems overlap with Module 5: you should be able to convert between decimal, binary, octal and hexadecimal by hand. Logarithms at this level are about the basic laws (log of a product, quotient and power), not tables.

Our Module 1 algebra note works through each type, and the algebra drill (Pro) gives you fresh numbers on every attempt.

1.3 Geometry

Geometry covers:

• (a) Simple geometrical constructions (B only): bisecting lines and angles, constructing shapes with given dimensions.
• (b) Graphical representation: the nature and uses of graphs, reading a value off a graph, graphs of equations and functions, gradient and intercept.
• (c) Trigonometry (B only): sine, cosine and tangent in a right-angled triangle, simple trigonometric relationships, rectangular and polar coordinates.

Without a calculator, trigonometry questions are built so that you need only the standard ratios (for example the sine of 30 degrees is 0.5) or a ratio you can form from given sides. Graph questions often ask what the gradient represents, so think about units: the slope of a distance against time graph is speed. The geometry, graphs and trigonometry note covers all three parts.

A worked example: a percentage question

Here is the kind of reasoning Module 1 tests. A fuel tank holds 2,400 litres. The gauge shows it is 35% full. How much fuel must be added to bring it to 80%?

1. The gap between the two levels is 80% minus 35%, which is 45% of the tank.
2. 10% of 2,400 litres is 240 litres, so 40% is 960 litres and 5% is 120 litres.
3. 45% is therefore 960 plus 120, which is 1,080 litres.

The procedural-error options are easy to predict. Someone who works out 80% of the tank (1,920 litres) and stops gives one wrong answer. Someone who works out 35% (840 litres) gives another. Breaking the percentage into 10% and 5% chunks is quicker and safer by hand than long multiplication.

Exam tip: Read the last line of the question again before you choose. Many wrong answers in Module 1 are correct answers to a slightly different question.

Calculators and the Module 1 exam

This is the question every Module 1 candidate asks, and the answer depends on where you sit the exam.

• CAA exam venues (UK): the CAA's aircraft maintenance licence examinations page lists what you may bring (a clear plastic pen, an eraser-tipped pencil and a sharpener) and bans electronic devices, watches and notes. Rough paper is supplied. Calculators are not on the approved list, and the page tells you to check your confirmation email for exam-specific items, as of October 2026.
• Part-147 organisations: each sets its own exam rules within its approval. Many run Module 1 without calculators. Ask before you book.
• EASA member state authorities: check with the authority or exam centre.

The safe plan is to prepare as if you will have no calculator at all. The syllabus does not need one: the questions are built around numbers you can handle on paper. Practise long multiplication and division, square roots of perfect squares, fraction arithmetic and powers of ten until they are automatic.

Building speed by hand

At 75 seconds a question you have time to work on paper, but not to work slowly. A few habits help:

• Learn the squares up to 15 and the cubes up to 5, and the common fraction and decimal pairs (one eighth is 0.125, three eighths is 0.375).
• Use powers of ten to keep numbers small: 0.004 times 3,000 is 4 times 3, which is 12.
• Estimate first. If the options are 1.2, 12 and 120, a rough estimate often picks the answer before you finish the sum.
• Check the options before you start a long calculation. Sometimes only one option has the right units or sign.

Work a full timed paper by hand at least once a week in the run-up to the exam, so the time limit stops feeling tight.

Which categories sit Module 1, and at what depth

Every category sits Module 1, and you can take it at any point. Most people sit it first, because Module 2 physics and Module 3 electrical fundamentals rely on the same skills: rearranging formulas, using powers of ten and converting units.

Category	Paper	Depth
A	16 questions	Arithmetic, simple algebraic expressions and graphs at level 1 or 2. No equations, constructions or trigonometry.
B1, B2, B2L	32 questions	Full syllabus, mainly level 2.
B3	32 questions (EASA) or 28 (UK)	Full syllabus, mainly level 2.

If you plan to go from category A to B1 later, sit the B-level paper from the start: an A pass does not count towards B1, while a B1 pass covers the A requirement. Practice papers for each category are on the category A Module 1 paper and the B1.1 paper linked above.

How our Module 1 practice works

The question bank behind this page has 326 original three-option Module 1 questions, 56 of them free. Each practice paper is built the same way as the real exam:

• three options, one correct, no negative marking
• 75 seconds per question and a 75% pass line
• choose EASA or UK CAA rules on the start screen, and the paper takes that length (this matters for B3)
• questions spread across 1.1, 1.2 and 1.3 in line with the AMC weighting
• calculation questions use templates, so the numbers change between papers and you cannot memorise answers

Every answer has an explanation, usually with why each wrong option is wrong. That matters in Module 1: knowing which procedural error leads to each distractor teaches you to spot the trap next time.

Free, without an account: paper 1 at full exam length, a 20-question quick practice with instant explanations, and a printable Module 1 sheet of 50 questions with an answer key, which you can save as a PDF. Neither EASA nor the CAA publishes past papers, so every question here is written for the app. Papers 2 to 10, the sub-module drills and all study notes come with Pro.

Common Module 1 mistakes

From the way the distractors are built, these are the errors to train out:

1. Unit conversions skipped or applied the wrong way. Multiplying by 1,000 instead of dividing when going from millimetres to metres.
2. Order of operations. Adding before multiplying in an expression without brackets.
3. Percentage change. Working the percentage off the new value instead of the original.
4. Inverse proportion treated as direct. More workers take less time, not more.
5. Index rules. Adding indices when dividing, or forgetting that anything to the power zero is 1.
6. Binary and hexadecimal. Reading place values from the wrong end.
7. Trigonometry. Using sine where the sides given call for tangent.

Write each wrong answer you make in practice into a short list with the rule you broke. Review that list, not the whole syllabus, in the last week before the exam.

Your study plan

1. Take the free B1.1 diagnostic (or the diagnostic for your category) to see where Module 1 sits against your other modules.
2. Read the arithmetic note, then work through algebra and geometry, paying most attention to equations if you are a B candidate.
3. Do the free quick practice without a calculator, then sit paper 1 under timed conditions.
4. Use the printable sheet for practice on the bus or between college blocks.
5. Book the exam when you score 85% or more on three different papers. Then move on to Module 2 physics and Module 3 electrical fundamentals, which use the same maths. If you are studying without a school, the Part-66 self-study guide and the exam format guide explain the rest of the process.