Percentage Problems - IELTS Academic Writing IELTS Study Notes
Overview
Imagine you're sharing a giant pizza with friends. Percentages help you figure out how much of that pizza each person gets, or how much is left after everyone takes a slice. They're super useful in everyday life, from understanding discounts in a store to seeing how much your favorite sports team's performance has improved. In the IELTS Academic Writing Task 1, you'll often see charts, graphs, and tables that use percentages to show changes or comparisons. For example, a graph might show the percentage of people who prefer different types of music, or how the percentage of students studying science has changed over ten years. Being good at understanding and explaining percentages isn't just about math; it's about telling a clear story with numbers. It helps you describe trends and make comparisons accurately in your writing, which is exactly what the IELTS examiners are looking for!
What Is This? (The Simple Version)
Think of a percentage (per-SENT-ij) like a special way to talk about parts of a whole. Imagine you have a delicious cake, and you cut it into 100 equal slices. If you eat 10 slices, you've eaten 10 percent (written as 10%) of the cake. It simply means 'out of 100'.
- 100% means the whole thing – all 100 slices of cake.
- 50% means half of the thing – 50 slices of cake.
- 25% means a quarter of the thing – 25 slices of cake.
So, when you see a percentage, just remember it's telling you how many parts out of a hundred you're looking at. It makes comparing different amounts much easier!
Real-World Example
Let's say your favorite video game costs $50. One day, the store announces a sale (a special price reduction)! The game is now 20% off.
How much money do you save? And what's the new price?
- Find the amount of the discount: 20% of $50.
- Remember, 20% means 20 out of 100. So, it's like saying (20/100) * $50.
- (0.20) * $50 = $10. So, you save $10!
- Find the new price: Original price - discount.
- $50 - $10 = $40. The game now costs $40!
See? Percentages help you quickly figure out how much money you save, just like that!
How It Works (Step by Step)
When you need to calculate with percentages, there are a few common things you'll do: 1. **To find a percentage of a number:** Change the percentage to a decimal (divide by 100) and then multiply it by the number. * Example: 25% of 80. Convert 25% to 0.25. Then, 0.25 * 80 = 20. 2. **To find...
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Key Concepts
- Percentage: A way to express a part of a whole as a number out of 100.
- 100%: Represents the entire quantity or the whole amount.
- Percentage Increase: How much a quantity has grown, expressed as a percentage of its original value.
- Percentage Decrease: How much a quantity has shrunk, expressed as a percentage of its original value.
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Exam Tips
- →Always clearly state whether you are describing a 'percentage' (e.g., 20% of people) or a 'percentage point' change (e.g., increased by 10 percentage points).
- →Practice converting percentages to decimals and fractions quickly to avoid calculation errors in your head or on scratch paper.
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