Smart Shopping
Learn how to compare prices, spot the best deals, understand discounts, and avoid advertising tricks.
Unit Pricing: Which Is the Better Deal?
Unit pricing means working out the cost per single item or per 100g. This helps you compare products that come in different sizes.
Example: Which cereal is cheaper?
Brand A — 500g
$5.00
$5.00 / 500g = $1.00 per 100g
Brand B — 750g
$6.00
$6.00 / 750g = $0.80 per 100g
Brand B is the better deal! It costs less per 100g even though the total price is higher.
How to calculate: Unit price = Total price / Number of items (or grams). Lower unit price = better value!
Sales and Discounts
Shops often have sales where they reduce prices. A discount is the amount taken off the original price.
How to Calculate a Discount
20% OFF a $50 backpack
Step 1: Find 20% of $50
20% = 20/100 = 0.20
$50 x 0.20 = $10 discount
Step 2: Subtract the discount
$50 - $10 = $40 sale price
10% off
Small discount
$100 item = $90
25% off
Quarter off
$100 item = $75
50% off
Half price
$100 item = $50
Advertising Tricks
Shops and advertisers use clever tricks to make you spend more. Being aware of these helps you make smarter choices.
"Limited Time Only!"
Creates urgency so you buy without thinking. Ask yourself: do I really need this?
"Buy 2, Get 1 Free"
Sounds great, but did you need three? You might end up spending more than planned.
Items Near the Checkout
Lollies and small items are placed at the checkout to tempt you while you wait.
Celebrity Endorsements
Just because a famous person uses a product doesn't mean it's the best or cheapest option.
Key Vocabulary
Unit Price
The price per single item or per standard amount (e.g. per 100g).
Discount
An amount taken off the original price, often shown as a percentage.
Sale Price
The new, lower price after a discount is applied.
Value for Money
Getting the most product or quality for the price you pay.
Worked Examples
A 6-pack of juice costs $12. A single juice costs $2.50. Which is better value?
6-pack: $12 / 6 = $2.00 per juice
Single: $2.50 per juice
Answer: The 6-pack is better value — $2.00 vs $2.50 per juice (saves 50c each).
A $40 t-shirt is on sale for 25% off. What is the sale price?
Step 1: Find 25% of $40: $40 x 0.25 = $10
Step 2: Sale price = $40 - $10 = $30
Brand A chips: 200g for $3. Brand B chips: 300g for $4. Which is cheaper per 100g?
Brand A: $3.00 / 2 = $1.50 per 100g
Brand B: $4.00 / 3 = $1.33 per 100g
Answer: Brand B is cheaper at $1.33 per 100g vs $1.50 per 100g.
Knowledge Check
Select the correct answer for each question. Click "Check Answer" to see if you are right.
Question 1
A 4-pack of muffins costs $8. A single muffin costs $2.50. What is the unit price of the 4-pack?
Question 2
A $60 game is on sale for 10% off. What is the sale price?
Question 3
A shop sign says "Buy 2 Get 1 Free" on $5 items. You buy 3 and pay for 2. What did each item actually cost you?
Question 4
Which advertising trick makes you feel like you need to buy something RIGHT NOW?
Question 5
A $80 jacket is 50% off. What do you pay?
Key Concepts Summary
- ●Unit price helps compare different-sized products. Lower unit price = better value.
- ●To find a discount: multiply the price by the percentage, then subtract.
- ●Bigger packs are often (but not always) cheaper per item.
- ●Advertisers use tricks like urgency, celebrity endorsements, and checkout displays.
- ●Always ask: "Do I really need this?" before buying.