How to Score Higher in OCR A Level Mathematics B (MEI) (H640)

• •Use μ — not X or P(X) — for the hypotheses; any other symbol almost always scores zero for both hypotheses.
• •Use the sample variance s² (unbiased), not the mean-squared deviation σ²; the software printout labels them differently.
• •For a two-tail test, compare the p-value with α/2, or use the two-tail critical region.
• •Never write an assertive conclusion such as 'this proves the mean has decreased' — always write 'there is sufficient/insufficient evidence to suggest …'.

• •Show the conjugate multiplication for each fraction on its own line — a one-line jump to the simplified form is treated as an unsupported calculator result.
• •Avoid trying to combine the fractions first into a common denominator; that approach fills a page and rarely succeeds within the time available.
• •Check that the denominator simplifies to an integer before moving on — algebraic errors here cause all subsequent marks to be lost.
• •Write the exact simplified form at each stage; converting to a decimal at any point forfeits the remaining marks.

• •Examiners penalise 'Newton's second law as a scalar equation' — always treat it as a vector equation.
• •Weight is (0, −mg): a particle of mass m in a field where j points upward has weight 0i − mg j, never +mg in the j component.
• •When finding velocity from acceleration, include the arbitrary constant as a vector: v = ∫a dt + c, where c is a constant vector found from initial conditions.
• •Speed = |v|; velocity = v. When the question asks for velocity, give the vector form, not the scalar magnitude.

• •The comprehension article is pre-released: read it thoroughly before the exam so that context doesn't slow you down on the day.
• •Many candidates left Section B blank in 2023 and 2024 — a partial attempt nearly always earns some marks, so attempt every part.
• •For 'show that' in Section B, three clearly annotated triangles (or other geometric objects) with dimensions labelled are often sufficient for the first marks.
• •Check whether a question refers to a formula on the article or a standard A Level formula — using the wrong one is the most common error in Section B.

• •Show the partial fraction decomposition fully — the coefficients must be found algebraically (substituting roots or comparing coefficients), not read from a calculator.
• •A common error: after integrating, writing y = (x − 1)³ − (x + 2)³ + 1024 instead of exponentiating correctly from ln y = ln(x − 1)³ − ln(x + 2)³ + ln 1024.
• •Include the modulus sign in each log term: ln|ax + b|, not ln(ax + b), since the argument may be negative in context.
• •If a boundary condition requires two equations to find the constant (e.g. the data comes in two parts), check the constant satisfies both equations before writing the final answer.

Derive the printed result with every intermediate step visible on the page. Each line must follow logically from the previous. The final line must match the printed result exactly. In comprehension Section B, a 'show that' question typically requires a clearly annotated diagram or explicit identification of the mathematical objects before the derivation.

Give a complete analytical method that demonstrates understanding of the mathematics behind the technique. Calculator solutions are not acceptable for these questions — every step must be shown in writing. In 2024 examiners offered the advice: 'you can use your calculator but make it look like you haven't.'

Find a result and justify it with supporting working or reasoning. Unlike 'find', this command requires visible method even when a calculator is available. Stating only the answer earns zero.

Establish a result using formal logic with no gaps. Algebraic proofs must manipulate rigorously from general assumptions to the required result. Proof by contradiction requires stating the assumption, deriving a contradiction, and concluding explicitly that the original claim must therefore be true.

Use the result or method from the immediately preceding part. Alternative methods that do not use the previous result score zero or very limited marks. Avoiding 'hence' always costs time and often costs marks.

Calculate the numerical or algebraic answer. Method marks are available for valid approaches even if the final answer is wrong — so show your working. Explicit method is not labelled but must be recoverable from the script.

Confirm a stated result using explicit mathematical working. Unlike 'show that', the result to be confirmed is given in the question — but full working and a concluding statement are still required.