Before opening a calculator, write down exactly what you are measuring. A useful heading is: examination year; subject title; subject level; syllabus code; candidate category; practice-paper source; date completed.

SEAB provides separate SEC syllabus directories for school candidates and private candidates, each with G1, G2 and G3 routes. Start with the relevant directory and read the current document for your subject. Do not assume that a familiar subject name identifies the right assessment arrangement.

For a school examination, use the school’s stated calculation rules. A weighted assessment, a preliminary examination and a national examination need not use an identical set of components. Ask whether a school total includes coursework, oral work, practical assessment or other components before trying to reproduce it.

Also distinguish a component weighting from an assessment-objective weighting. A component weighting tells you how much a component contributes to the overall result. An assessment-objective weighting describes the intended balance of skills assessed. These are different views of an assessment. They are not extra percentages to add to the same calculation.

If the instructions use subcomponents, optional routes or special aggregation rules, follow those instructions rather than forcing the assessment into the simple example below. The method in this guide assumes components that are combined by their stated percentage weights.

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Imagine earning 56 marks out of 80. Your raw score is 56/80. Your component percentage is 70%. Neither number tells you the component’s contribution to the whole subject until you know its weighting.

If that component carries 50% of the overall practice result, its contribution is 35 percentage points: 56 ÷ 80 × 50 = 35.

These three descriptions answer different questions:

• Raw marks: How many marks did I earn on this task?
• Component percentage: What proportion of the available marks did I earn?
• Weighted contribution: How much does that performance contribute to the combined practice score?

Write “35 percentage points towards the total” rather than “35% on the paper”. The student actually achieved 70% on the paper. Confusing these quantities can make a reasonable performance look much weaker than it is.

A weighting is not a bonus. Multiplying by 50 does not add 50 marks. It scales performance into a component’s share of a 100-point overall result. A perfect score on a component weighted at 50% contributes 50 points, not 100.

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The following three-component assessment is invented solely to explain the arithmetic. It is not the official format for any named SEC subject. Replace every maximum mark and weighting with the verified figures for your own assessment.

The weighted practice score is therefore 72%. Component A and Component B both have a component percentage of 70%, but they contribute different amounts because their weights differ. Component C has a percentage of 80% and contributes 16 points.

Now compare the tempting shortcut. Adding the raw marks gives 107 out of 150, or approximately 71.33%. That does not equal 72%, because the maximum raw marks do not have the same proportions as the stated weights.

An equally weighted average is also wrong here. Averaging 70%, 70% and 80% gives approximately 73.33%. That treats every component as one-third of the subject when the actual hypothetical shares are 50%, 30% and 20%.

Before accepting your answer, make two checks. The component weights must add to 100%, and each contribution must lie between zero and its assigned weighting. In this example, Component B cannot contribute more than 30 points. An answer above that tells you something has gone wrong in the formula or inputs.

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Suppose you have completed only Components A and B. You know that they contribute 35 + 21 = 56 points out of the 80 points available from those components. Component C, representing the remaining 20%, has not been assessed.

Do not report “overall score: 56%”. That can be misread as a complete result. Do not enter a zero for C merely to make the spreadsheet work. “Not assessed” and “assessed and awarded zero” mean different things.

A clear record would say:

• Completed components: A and B, covering 80% of the hypothetical assessment.
• Contribution recorded so far: 56 points towards a possible 100.
• Performance within completed components: 56 ÷ 80 × 100 = 70%.
• Overall practice score: incomplete.

The 70% figure is useful, but it describes only the completed portion. It is not evidence that the student would achieve 70% on the missing component.

You may explore a clearly labelled scenario: if C were 12/20, the total would be 56 + 12 = 68%. That is a planning assumption, not a result. Keep scenarios in a separate column so they cannot silently become reported achievement.

An actual missed examination component is different from unfinished home practice. Ask the school or SEAB about the applicable procedure. A home spreadsheet cannot decide the treatment of absence, exemptions or special consideration.

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Create columns for component name, marks earned, maximum marks, weighting, contribution, marking status and notes. Record the source of each weighting alongside the sheet, including the syllabus year or school instructions used.

For a spreadsheet, if earned marks are in B2, maximum marks in C2 and the weighting is entered as the number 50 in D2, the contribution formula is =B2/C2*D2. The result is expressed in percentage points.

If D2 is entered as 50%, it is stored as 0.5. In that arrangement, =B2/C2*D2 returns 0.35, which should be displayed as 35%. Both conventions can work. Mixing them can make a result one hundred times too large or too small.

Keep the full calculated value in the cell and round only the final display. For example, 37/60 weighted at 30% contributes exactly 18.5 points. Rounding the component percentage first to 62% would instead produce 18.6 points. That difference is small, but unnecessary.

Check these conditions before summing:

• Every maximum mark is greater than zero.
• Earned marks do not exceed the maximum.
• Each component appears once, without duplication.
• Weights come from the same assessment arrangement and total 100%.
• All included scores have been marked, rather than merely attempted.
• The practice conditions are recorded: timed, untimed, open-book or supported.

Do not hide uncertainty behind decimal places. An essay that you marked generously yourself does not become an exact measurement because a spreadsheet displays 72.438%. Record the uncertainty and seek feedback where it matters.

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SEAB’s SEC information states that G1, G2 and G3 retain the grading structures associated with N(T), N(A) and O-Level subjects respectively. It also states that the SEC maintains overall examination standards. These statements do not make a self-marked practice percentage an official grade forecast. See SEAB’s SEC overview.

For GCE-Level examinations, SEAB explains that it cannot convert grades into marks using predetermined cut-offs; grading considers factors including paper difficulty and the quality of candidates’ work. That is a clear reason not to present a borrowed percentage chart as a guaranteed national-examination conversion. See SEAB’s explanation of grade-to-mark conversion.

Likewise, SEAB’s explanation of GCE grading rejects predetermined proportions of candidates receiving particular grades. Do not use classmates’ estimated marks to invent a bell curve for your own result. See SEAB’s grading FAQ.

A school may use a stated reporting scale for its own assessments. You can report that school grade under the school’s rules, while keeping it separate from a future national result. “72% on this marked practice set” is an honest statement. “Therefore a guaranteed SEC distinction” is not.

For mixed-level subjects, do not invent a percentage multiplier to turn a G2 paper into a G3 paper. SEAB’s published grade mapping concerns particular post-secondary aggregate calculations; it is not a formula for equating practice marks across different levels.

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Return to the hypothetical assessment. One extra raw mark in A contributes 50 ÷ 80 = 0.625 overall points. One extra mark in B contributes 30 ÷ 50 = 0.6 points. One extra mark in C contributes 20 ÷ 20 = 1 point.

This does not mean “ignore A and B because C is more valuable per mark”. The tasks may differ substantially in difficulty, time and reliability. A component’s marks are not interchangeable units of effort.

Instead, compare realistic improvements. Raising A from 56 to 64 would add five overall points. Raising C from 16 to 18 would add two. Both could be worthwhile. The better next task depends on why marks were lost and what the student can reasonably improve.

Use three questions:

1. Which error appears repeatedly rather than just once?
2. What specific action could address it?
3. How will I check that the improvement transfers to a new question?

For example, “practise more” is vague. “Complete three unfamiliar questions requiring unit conversion, explain each conversion, then retry a fresh timed question next week” is testable. An essay weakness might call for teacher feedback on argument development rather than another unmarked essay.

Keep an error note beside each component score. A rising total can hide a persistent weakness in one component; a falling total may reflect a harder practice set rather than lost ability. Compare conditions and question demands before judging the student.

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Can I add all my marks and divide by all available marks?

Only when that reproduces the specified weighting. The three-component example shows why it may not. Calculate component contributions separately when the scheme supplies percentage weights.

Does the biggest paper deserve most of my revision time?

Its weighting matters, but so do current weaknesses and the time required to improve them. Maintain every assessed skill and prioritise repairs that are both important and achievable. Avoid abandoning a smaller component entirely.

Can I combine scores from different months?

You can make an illustrative practice profile, but label the dates and conditions. A January score and a November score do not describe one examination sitting. Do not present such a mixture as a precise measure of current readiness.

What if I used help or checked the answer midway?

Record that attempt as supported practice. It can show learning, but it is not directly comparable to an independent timed attempt. Use a fresh question later to see what you can do without help.

Should I round each paper before adding the contributions?

For your own practice analysis, retain precision and round the displayed total at the end. If reproducing a school report, follow the school’s stated calculation and rounding rules instead.

What should I do today?

Choose one subject. Confirm the correct assessment scheme, enter one complete marked practice set, and check the weights and formulas. Then identify one recurring error and choose one repair task. The useful outcome is a better next attempt, not a more elaborate prediction of a grade you have not yet received.

Source check: 11 November 2026. The worked assessment and revision examples are original illustrations, not SEAB paper specifications or grading rules. Refer to the current official syllabus and your school’s instructions for the assessment you are taking.

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