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Mathematics · Lessons

Organise working for a multi-operation task

A long calculation goes wrong not because one step is hard but because the steps are piled together on the page.

On this page
  1. How do you lay out a long question?
  2. Worked example
  3. The mistake to watch for
  4. Check yourself
  5. Where this leads next

To organise a long calculation, split it into labelled stages, finish each stage on its own line, and only then combine the results. Brackets and powers come first, then multiplication and division, then addition and subtraction.

This skill belongs to non-calculator strategy and uses the fraction moves from choosing an efficient fraction method.

How do you lay out a long question?

  1. Read the whole question and find the operations inside each bracket.
  2. Label stages A, B, C. Each stage is one bracket or one operation.
  3. Solve each stage separately and write its value clearly.
  4. Combine the stage results in a final line, in the right order.
  5. Check the size of the final answer with a quick estimate.

Labels cost five seconds each. They also make it easy to find one slip among many correct lines.

Worked example

Work out (2/3 + 1/4) ÷ (5/6 − 1/3), giving the answer as a mixed number.

Stage A, first bracket: 2/3 + 1/4. The lowest common denominator is 12. So 8/12 + 3/12 = 11/12.

Stage B, second bracket: 5/6 − 1/3. The common denominator is 6, and 1/3 = 2/6. So 5/6 − 2/6 = 3/6 = 1/2.

Stage C, combine: 11/12 ÷ 1/2 = 11/12 × 2/1. Cancel 2 with 12 to get 1 and 6. This gives 11/6.

Stage D, convert: 11/6 = 1 5/6.

Check: 2/3 + 1/4 ≈ 0.667 + 0.25 = 0.917, and 5/6 − 1/3 = 0.5. Then 0.917 ÷ 0.5 = 1.833, which matches 1 5/6.

The mistake to watch for

A common error is to add fractions by adding the tops and the bottoms.

Mistaken working: 2/3 + 1/4 = 3/7

The numerators were added (2 + 1) and the denominators were added (3 + 4).

The result 3/7 is about 0.43, which is smaller than 2/3 alone. Adding a positive number cannot make the total smaller, so the answer is impossible. The correct approach is a common denominator: 8/12 + 3/12 = 11/12.

Check yourself

Try these without a calculator, then open each answer.

1. Work out (5/8 − 1/4) × 4/3.

Show answer

Stage A: 5/8 − 2/8 = 3/8. Stage B: 3/8 × 4/3. Cancel 3 with 3 and 4 with 8 to get 1/2. The answer is 1/2.

2. Work out 3/5 + 2/3 × 3/4.

Show answer

Multiplication comes first: 2/3 × 3/4 = 6/12 = 1/2. Then 3/5 + 1/2 = 6/10 + 5/10 = 11/10, which is 1 1/10.

3. A shirt costs RM60. The price is cut by 25%, and the new price is then cut by a further 10%. What is the final price?

Show answer

Stage A: 60 × 0.75 = RM45. Stage B: 45 × 0.9 = RM40.50. The second cut applies to RM45, not RM60.

Where this leads next

The next lesson compares two ways of doing the same calculation: compare two valid mental strategies. When you are ready, try the non-calculator strategy practice set. The percentage-base explorer shows each stage of chained percentage changes, and the non-calculator working trainer does the same for fraction steps.

A teacher who sees how you actually lay out a page can often spot a layout habit that causes repeated slips. That is part of what we look at in online one-to-one Mathematics tuition.

Questions people ask

Why does layout matter if the maths is right?

Because when the working is cramped you cannot find your own error, and an examiner cannot follow the method to award method marks. Labelled stages let you check each one separately and show exactly where the reasoning sits.

Should I work out brackets first even if they look hard?

Yes. Brackets come first in the order of operations, so each bracket is a separate mini-problem. Solve each one fully, write the result, and then combine. This is easier than trying to do everything in one line.

How many lines of working should a question have?

As many as you need to keep each line to a single idea. One operation per line is a good rule for long fraction or percentage questions. You do not need to write out trivial mental steps, but every stage that changes the structure should appear.

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Your next step

If you lose track of your own working in longer questions, a one-to-one teacher can look at how you lay out a page and help you set it up so errors become visible.

Paid one-hour trial at your assigned teacher’s confirmed rate, starting from RM80. You agree the teacher’s hourly rate before the trial, and ongoing lessons continue at that same rate. The schedule is arranged with your teacher after the trial.

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