Learning pack · IGCSE handout

Percentages

What's in this pack: printable worksheet PDF, matching answers PDF (IGCSE / Secure–Stretch practice). Percentages are hundredths. Multipliers turn increase/decrease and reverse-percentage problems into one-line calculations.

Resources at the top · full summary · videos with short notes below.

🎒 Resources in this pack

Jump straight to the printable files, or scroll to the summary and videos.

Scaffolded Learning Sheet — attempt the worksheet, then use the Answers for a full written solution.

📝 Open Learning Sheet ✅ Open answers 🎬 More topic videos (6)📖 Full summary

Files: 18_percentages_handout.pdf · 18_percentages_handout_answers.pdf

Full topic summary

Percentages are hundredths. Multipliers turn increase/decrease and reverse-percentage problems into one-line calculations.

Key learning points

Percentage of an amount: $\frac{p}{100}\times\text{amount}$ .
Increase by $p\%$ : multiply by $1+\frac{p}{100}$ ; decrease by $1-\frac{p}{100}$ .
Reverse percentage: divide by the multiplier that created the new amount.

Worked example 1 — Percentage of an amount

Find $15\%$ of $£80$ .

Working

0.15\times80=12

Use a decimal multiplier.

Worked example 2 — Percentage increase

Increase $£50$ by $12\%$ .

Working

50\times1.12=56

Multiplier $1+\frac{p}{100}$ .

Worked example 3 — Percentage decrease

Decrease $200$ by $25\%$ .

Working

200\times0.75=150

Multiplier $1-\frac{p}{100}$ .

Worked example 4 — Reverse percentage

After a $20\%$ increase a price is $£72$ . Find the original.

Working

72\div1.2=60

Divide by the increase multiplier.

🎬 Topic videos

Math Antics - What Percent Is It?
Math Antics · 8 min
Lower Secondary classroom-friendly explainer. Scaffold→stretch friendly; use with mixed-ability groups.
Math Antics - Percents And Equivalent Fractions
Math Antics · 9 min
Lower Secondary classroom-friendly explainer. Scaffold→stretch friendly; use with mixed-ability groups.
Math Antics - Percents Missing Total
Math Antics · 5 min
Lower Secondary classroom-friendly explainer. Scaffold→stretch friendly; use with mixed-ability groups.
Math Antics - Calculating Percent Change
Math Antics · 13 min
Lower Secondary classroom-friendly explainer. Scaffold→stretch friendly; use with mixed-ability groups.
Strategies for Mentally Calculating Percentages
Eddie Woo · 11 min
Lower Secondary classroom-friendly explainer. Scaffold→stretch friendly; use with mixed-ability groups.
Percentage Increase/Decrease (1 of 2: The Potato Paradox)
Eddie Woo · 8 min
Lower Secondary classroom-friendly explainer. Scaffold→stretch friendly; use with mixed-ability groups.

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Browse the hub Learning Packs & Summary, or open the compact Percentages summary.