mathematics

John Erritt

John Erritt is a mathematics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand John Erritt rather than just read about it. In short: Michael John Mackey Erritt, CB (15 February 1931, Belfast - 3 October 2002, Lindfield, Sussex) was the Deputy Director of the British Government Statistical Service. Education St Andrew's College, Dublin Prince of Wales School, Nairobi Queen's University, Belfast (BSc (Econ)).

Key takeaways

John Erritt belongs to mathematics; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect John Erritt to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of John Erritt from memory before moving on to harder problems.

Reference excerpt

Michael John Mackey Erritt, CB (15 February 1931, Belfast - 3 October 2002, Lindfield, Sussex) was the Deputy Director of the British Government Statistical Service.

Education St Andrew's College, Dublin Prince of Wales School, Nairobi Queen's University, Belfast (BSc (Econ)).

Career Research Officer, Science and Industry Committee, 1953 Assistant Statistician, Central Statistical Office, 1955 Statistician: Board of Trade, 1960; H.M. Treasury, 1964; Board of Trade, 1967 Chief Statistician: Inland Revenue, 1968; Central Statistical Office, 1973; Departments of Industry, Trade and Prices and Consumer Protection, 1975; Ministry of Defence, 1979 Assistant Under-Secretary of State and Director of Statistics, Ministry of Defence, 1981 Assistant Director, Central Statistical Office, 1985-1991; Deputy Director, Government Statistical Service, 1989-1991. He moved from the MoD back to the CSO because Michael Heseltine ordered a reduction in the number of statisticians in the MoD and his post was downgraded.

References Who was Who

Worked examples

Example 1 — a first encounter with John Erritt

Start with the simplest possible case. Write down what John Erritt claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In mathematics, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to John Erritt before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about John Erritt ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of John Erritt

In research: John Erritt appears in mathematics research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses John Erritt in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: John Erritt is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1931 births, 2002 deaths, 20th-century English mathematicians, so understanding it makes those chapters shorter.
In everyday life: Look for John Erritt outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study John Erritt in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what John Erritt means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain John Erritt out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is John Erritt in simple terms?

Michael John Mackey Erritt, CB (15 February 1931, Belfast - 3 October 2002, Lindfield, Sussex) was the Deputy Director of the British Government Statistical Service. Education St Andrew's College, Dublin Prince of Wales School, Nairobi Queen's University, Belfast (BSc (Econ)).

Why does John Erritt matter?

Because it connects several mathematics ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study John Erritt?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on John Erritt.