Additional Math 0606: what examiners say, session after session

Examiner reports for Cambridge Additional Mathematics 0606 repeat the same few messages in almost every session. They apply to every topic and to both papers. This guide gathers them in one place. Each topic has its own guide with the mistakes for that topic, and there are short guides for Paper 1 and Paper 2.

This guide is based on a reading of Cambridge examiner reports for recent sessions. The advice is summarised in our own words.

Message 1: Read the question, give the answer in the form asked

This is the most repeated message. Candidates are advised to read each question carefully, make sure the demands are fully met, and check the final answer before moving on. The reports give many examples of the form of an answer:

• an equation of a line in the form ax + by + c = 0 with integer coefficients, or including the "y" in the equation;
• a single logarithm, when the question asks for one;
• a domain or range written as an inequality in terms of the right variable;
• a single value when the question says "least value", not an inequality;
• the requested quantity at the end of an optimisation question, not an intermediate value.

Candidates are also told to check for a "key word or phrase", and to read the question again once they have finished.

Message 2: Exact means exact

• An exact answer is written as a surd, in terms of π, or as a fraction. Decimals are not needed with an exact answer, and the reports say that where exact answers are asked for, a decimal answer will not earn the final accuracy mark.
• Fractions and terminating decimals are exact values and do not need to be rounded.
• Too many candidates still give an answer to 3 significant figures when the question asks for an exact one.

Message 3: Accuracy for the other answers

• When no accuracy is stated, the rubric on the front page of the paper applies: non-exact answers to 3 significant figures, and angles in degrees to one decimal place.
• Work to at least 4 significant figures during the calculation, so that the final answer is correct to 3.
• Do not round early. Where a question gives a value to a lower accuracy, show a more accurate value before rounding.
• When finding angles in radians, keep the calculator in radian mode. Converting from degrees introduces rounding errors.

Message 4: Show the method

• No marks are given for unsupported answers from a calculator. The reports repeat this in many sessions.
• When a value is incorrect and the method used to find it is not shown, no marks can be given. For follow-through marks, the method of calculation must be seen, because correct method will not be assumed from incorrect values.
• In "show that" questions, every step has to be shown clearly. If you do not obtain the given result, check your earlier work rather than contriving to obtain it.
• Combining steps into a simplified form (as a calculator would) cannot be credited.
• Examiners say the same about calculus: substitution of limits, and of values into a derivative, should be shown.

Message 5: "Hence" and linked parts

When a question says "hence", it expects you to use the result from the previous part. The reports add that the word will not always be used, so candidates should consider whether an earlier part is meant to help with a later one. A solution that ignores this is likely to be longer and to omit necessary working.

Message 6: Sketches and diagrams

• State the coordinates of the points where a curve or line meets the axes. Omitting them often results in an unnecessary loss of marks.
• Complete the sketch in full, as accurately as possible, with some labelling.
• Where a diagram is given, use it, and make more use of diagrams generally.

Message 7: Calculators are for checking

• Check that the calculator is in the right mode (radians or degrees) at the start of each question with angles.
• Use algebraic methods when solving equations. Candidates should not rely on a calculator to solve quadratic equations, to evaluate derivatives or integrals, or to eliminate an unknown in a pair of linear simultaneous equations.
• Trial and improvement, used early, is likely to omit necessary working.
• If a specific method is requested (for example a graph), another method is unlikely to be credited.

Message 8: Presentation and the question paper

• Refer to the list of formulas on page 2 when in doubt, and read the rubric on the front page before the exam.
• Cross out errors and replace them. Work on additional pages should be labelled with the question number, even when it is rough work.
• Use the mark allocation and the answer space as a guide to how much work is expected.
• Write clearly, so that you do not misread your own work.

Before you move on

After every Additional Math worksheet, ask yourself:

1. Did I give each answer in the form the question asks for?
2. Did I leave exact answers exact, and keep working to at least 4 significant figures?
3. Is the method for every mark written down?
4. Did I use "hence" and the earlier parts?
5. Did I label the intercepts and key points on every sketch?

Questions students ask

What do examiners say most often about Additional Math 0606?

Read the question and give the answer in the form asked. It is the most repeated message. Examples: a line as ax + by + c = 0 with integer coefficients or including the "y", a single logarithm when one is asked for, a domain or range as an inequality in the right variable, and a single value when it says "least value".

What does "exact" mean in Additional Math?

A surd, an answer in terms of π, or a fraction. Decimals will not earn the mark where an exact answer is asked for. Fractions and terminating decimals are exact and do not need rounding.

How many significant figures do I give in Additional Math?

When no accuracy is stated, non-exact answers are given to 3 significant figures and angles in degrees to one decimal place. Work to at least 4 significant figures and do not round early.

Can I rely on my calculator in Additional Math?

Use it to check, not to replace working. No marks are given for unsupported calculator answers, combining steps as a calculator would cannot be credited, and trial and improvement used early is likely to omit necessary working.

Why must I state intercepts on a sketch?

Omitting the coordinates of the points where a curve or line meets the axes often results in an unnecessary loss of marks. Complete the sketch in full, with some labelling.