About this worksheet

This free Year 8 percentage change worksheet is written for the Western Australian curriculum and mapped to SCSA content description WA8MNAC1. It targets one skill so students can practise until it sticks: by the end, students can say “I can calculate percentage change, profit and loss percentages, and work backwards to find an original amount.”

What’s inside

• Key idea box – a short explanation with worked examples to read before starting.
• A · Fluency (16 questions) – quick practice to build accuracy.
• B · Core (10 questions) – worded problems set in everyday Australian contexts.
• C · Reasoning (4 questions) – explain, justify and spot the error.
• D · Challenge (4 questions) – harder multi-step and problem-solving questions for students ready to stretch.
• Separate marking key – every answer with working, plus mark allocations and marking criteria for reasoning questions.

Skills covered

• Calculating percentage change, profit and loss
• Working backwards to find an original amount
• Removing GST from a total

How to use this worksheet

Start with the Key idea box, then complete Section A (use a calculator only where a question says so). Most students should attempt Sections B and C; Section D suits students aiming for the top of the class or preparing for accelerated or extension maths. The worksheet is marked out of 58, and the score box on the last page helps students see which section needs more practice.

Common mistakes to watch for

• Dividing by the new amount instead of the original
• Taking 10% off a GST-inclusive price to remove GST
• Subtracting the percentage from the sale price to reverse a discount
• Ignoring unsold stock when finding profit

Where this fits in the WA Year 8 sequence

Percentage Change and Original Amounts sits in the Calculating with number sub-strand of Number and algebra. It is one of a set of short, single-skill EduLift worksheets that split each Year 8 content description into sub-skills. Use the previous and next links to work through the sequence in order.

Common errors we see in tutoring

• Dividing by the new amount instead of the original
• Taking 10% off a GST-inclusive price to remove GST
• Subtracting the percentage from the sale price to reverse a discount
• Ignoring unsold stock when finding profit