Chapter 4.7: Best value and unit pricing

🎯 Learning Journey

Identify Quantities and Prices

START: Look at each option and identify the quantity (weight, volume, number) and the total price for that quantity.

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Calculate Price Per Unit for Each Option

CALCULATE: Divide the total price by the quantity to find the cost per unit (per gram, per liter, per item, etc.).

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Compare Unit Prices

COMPARE: Look at all the unit prices side by side. The option with the lowest unit price gives the best value for money.

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Identify Best Value Option

IDENTIFY: Choose the option with the lowest cost per unit as the best value. This gives you the most product for your money.

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Consider Other Factors Like Quality and Need

CONSIDER: Think about other factors like quality, expiry dates, and whether you actually need that much quantity before making your final decision.

📖 Understanding the Topic

🎯 What You'll Learn

Unit pricing helps you compare the value of different products by calculating the cost per unit (per gram, liter, item, etc.). This skill is essential for smart shopping and finding the best deals. Understanding unit pricing ensures you get the most value for your money and can make informed purchasing decisions.

🚀 Why This Matters

Comparing Prices in Different Sized Packages

Supermarkets offer products in various sizes, and the biggest isn't always the best value. Unit pricing helps identify genuine bargains.

Shopping for Best Deals

Smart shoppers use unit pricing to save money on groceries, household items, and other purchases throughout the year.

Budget Management

Families and businesses use unit pricing to maximize their purchasing power and stay within budget constraints.

💡 Worked Examples

Cereal prices: 400g box £3.20, 600g box £4.50

Which better value?

Solution:
400g box: £3.20 ÷ 400g = £0.008 per g = 0.8p per g
600g box: £4.50 ÷ 600g = £0.0075 per g = 0.75p per g
Answer: 600g box is better value (0.75p vs 0.8p per gram)

Petrol: Station A 45p/liter, Station B £22.50 for 50 liters

Which cheaper?

Solution:
Station A: Already given as 45p per liter
Station B: £22.50 ÷ 50L = £0.45 per liter = 45p per liter
Answer: Both stations charge the same price (45p per liter)

Pizza: Medium 25cm £12, Large 35cm £18

Compare value if price depends on area

Solution:
Medium area: π × (12.5)² ≈ 491 cm²
Large area: π × (17.5)² ≈ 962 cm²
Medium: £12 ÷ 491 ≈ £0.024 per cm²
Large: £18 ÷ 962 ≈ £0.019 per cm²
Answer: Large pizza is better value

✏️ Practice Questions

Question 1: 3 apples cost £1.50. Cost per apple?

Question 2: Compare: 500g for £2.50 vs 750g for £3.60. Which is better value?

Question 3: Which is cheaper per liter: 2L for £3.20 or 3L for £4.50?

⚠️ Common Mistakes & How to Avoid Them

Learn from typical errors students make and discover how to avoid them!

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Common Misconceptions

What students often do wrong:

1. Assuming larger packages are always better value: Thinking bigger size automatically means better deal without calculating unit prices

2. Not calculating actual cost per unit: Comparing total prices instead of working out price per gram, liter, or item

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How to Avoid These Mistakes

Correct approach: Always calculate the unit price by dividing total cost by quantity. Compare unit prices, not package sizes or total costs.

Memory tip: "Unit price tells the truth" - smaller packages sometimes offer better value than large ones

💡 Teacher's Tip

Bring real product examples to class or use supermarket flyers. Let students calculate unit prices for actual products they recognize - this makes the learning relevant and practical.

📋 Chapter Summary

🎉 Congratulations!

You've mastered Best value and unit pricing!

🎯 Skills You've Developed:

✓ Calculating unit prices to compare value

✓ Determining best value options

✓ Applying unit pricing in shopping contexts

✓ Making informed purchasing decisions

🚀 What's Next?

Next: Learn about proportion in maps and diagrams to understand scale and calculate real distances