Exam mix: directed numbers and percentages

2026-12-14Exam & Challenge Mr Ng

Short mixed set switching between signs and percentage multipliers.

Key formulas

\text{Reset method each question}

What this lesson covers

This lesson builds Secondary 2–3 skill in exam directed percent. 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 (exam directed percent) 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 — exam directed percent

Problem. Apply the method for exam directed percent with the numbers 4 and 5.

Solution. Identify the rule for exam directed percent. Substitute 4 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 exam directed percent: what is 3+4?

Practice questions

Practice 1 on exam directed percent: compute with the value 12.
Practice 2 on exam directed percent: change the numbers and repeat the same method.
Practice 3 on exam directed percent: write one sentence explaining the key rule.
Practice 4 on exam directed percent: invent a similar exam-style question and solve it.

Study notes

What is the main idea of exam directed percent?

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.