Forming equations from word problems

Translate sentences into a single linear equation before solving.

Key formulas

Define the unknown first\text{Define the unknown first}

What this lesson covers

This lesson builds Secondary 2–3 skill in forming equations. Read the key formulas, study the worked example, then attempt the written practice and the four-question MCQ review.

Method

Write every step. Name the rule you use (forming equations) before substituting numbers. Keep units and signs visible until the final sentence.

Common mistakes

Students often rush the sign, use the wrong percentage base, or cancel terms instead of factors. Pause after each line and ask whether the step is reversible.

Exam habit

Underline the question verb (simplify, solve, factorise, find). Box the final answer and, where sensible, substitute back for a quick check.

Worked example

Worked example — forming equations

Problem. Apply the method for forming equations with the numbers 8 and 5.

Solution. Identify the rule for forming equations. Substitute 8 and 5 carefully with signs in brackets if needed. Complete each operation on a new line. State the final answer clearly and check by reversing one step.

Review quiz

1 / 4

Warm-up on forming equations: what is 9+6?

Practice questions

  1. Practice 1 on forming equations: compute with the value 44.
  2. Practice 2 on forming equations: change the numbers and repeat the same method.
  3. Practice 3 on forming equations: write one sentence explaining the key rule.
  4. Practice 4 on forming equations: invent a similar exam-style question and solve it.

Study notes

What is the main idea of forming equations?

Apply the stated formula or rule with clear steps, then check by reversing or substituting.

How should I revise this topic?

Cover the worked example, redo the practice without notes, then complete the MCQ set and log any wrong options.

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