🧙 Money Magic: Coins, Change & Discounts

Master shopping maths — discounts, VAT, change and multi-step money puzzles — to unlock the Maths Castle treasure vault!

🧙 Welcome, young apprentice, to the shimmering coin-filled halls of the Maths Castle! Did you know that shops actually use maths tricks every single day to make deals look extra tempting? When you see a sign screaming '20% OFF!' or 'BUY ONE GET ONE HALF PRICE', someone has carefully calculated exactly how much money you'll save — and how much they'll still earn. Money maths is one of the most useful skills you will EVER learn, because you'll use it for the rest of your life: buying sweets, saving pocket money, working out if a bargain is really a bargain, and one day paying bills. Imagine you have £10 birthday money and you spot a game costing £6.99. Can you afford it AND a £2.50 drink? A wizard of money can answer instantly! In the 11+ exam, money questions test whether you can work with pounds and pence, calculate percentages, and give the correct change — all under pressure. By the end of this lesson, you'll be able to snap through these problems like casting a spell. So grab your enchanted purse, apprentice, and let's turn you into a true Money Wizard! ⭐

So what exactly IS money maths? At its heart, it's simply **decimals and place value** wearing a fancy costume. Think of money like this: every amount has **pounds** on the left of the decimal point and **pence** on the right. Because there are 100 pence in a pound, money always uses exactly **two decimal places** — so £3.40 means three pounds and forty pence, NOT three pounds and four pence. Picture a pound coin sliced into 100 tiny equal pieces, just like a chocolate bar broken into 100 squares — each square is one penny. When you write £2.05, that zero is holding the 'tens of pence' place empty, showing you have five pennies and no ten-pence coins. Getting the **decimal point** in the right spot is the golden rule of money magic. A common wizard's warning: £1.5 is a mistake — you must write £1.50 to show fifty pence, because 5 in the first decimal place means five ten-pence coins, which equals fifty pence! Once you see money as decimals split into pounds and pence, every calculation — adding, subtracting, or finding percentages — becomes far less mysterious.

Now, how does money maths actually work when we calculate? The **four operations** — adding, subtracting, multiplying and dividing — all apply, but you must keep the **decimal points lined up** neatly, one under the other. Let's say you buy items costing £2.30 and £1.45. Stack them: £2.30 on top, £1.45 below, points aligned, then add each column: 0+5=5 pence, 3+4=7, so 75 pence; 2+1=3 pounds. Total: **£3.75**. For **change**, you subtract the cost from the money you handed over. Pay with £5.00 for something costing £3.75? Do 5.00 − 3.75 = **£1.25** change. A brilliant wizard's shortcut is **counting up**: start at £3.75, add 25p to reach £4.00, then add £1 to reach £5.00 — that's £1.25 altogether! For **percentages** (used in discounts and VAT), remember that 'per cent' means 'out of 100'. To find 10%, divide by 10; to find 1%, divide by 100; to find 25%, divide by 4. A **discount** is subtracted from the price, while **VAT** (a tax of 20% in the UK) is added on top. Keep these rules sharp and no money puzzle can defeat you!

Here is the Wizard's step-by-step method for conquering ANY money problem. **Step 1:** Read the whole question carefully and underline what it's actually asking — change? total? discount? Don't rush! **Step 2:** Write every amount in the same format, with two decimal places (£4.50, not £4.5). **Step 3:** Decide which operation you need. Words like 'altogether' and 'total' mean add; 'change' and 'how much less' mean subtract; 'each' can mean multiply or divide; 'off' or 'discount' means subtract a percentage. **Step 4:** For percentages, find 10% first (divide by 10) as your anchor, then build up — 20% is double 10%, 5% is half of 10%. **Step 5:** Line up your decimal points and calculate carefully, column by column. **Step 6:** For multi-step questions, do the discount FIRST, then add VAT to the new, smaller price. **Step 7:** ALWAYS check your answer makes sense — change should be less than what you paid, and a discounted price should be lower than the original. **Step 8:** Write the answer with the £ sign and two decimal places. Follow these eight steps like a treasure map and you'll never lose your way! 🎯

Let's cast a simple spell together. **Question:** Freya buys a magic pencil for £1.65 and a sticker for £0.90. She pays with a £5 note. How much change does she get? **Step 1** — What's asked? The change. **Step 2** — Find the total cost first. Line up: £1.65 + £0.90. Add pence: 5+0=5, then 6+9=15 (write 5, carry 1), then 1+0+1=2. Wait, let me be careful: 1.65 + 0.90 — pence column 5+0=5; ten-pence column 6+9=15, so write 5 and carry 1; pounds 1+0+1=2. Total = **£2.55**. **Step 3** — Now find the change from £5.00. Do 5.00 − 2.55. Use counting up: from £2.55, add 45p to reach £3.00, then add £2 to reach £5.00. That's 45p + £2 = **£2.45**. So Freya gets £2.45 change. **Check:** her change (£2.45) is less than the £5 she paid — that makes sense! Notice how finding the total FIRST, before working out change, kept everything tidy. If you tried to subtract each item separately you could still get there, but doing it in two clean stages is far safer under exam pressure. Well cast, apprentice! ⭐

Now a trickier two-step spell with a wrinkle. **Question:** A jumper costs £40. In a sale it has 15% off. How much does it cost now? Many apprentices freeze at 15% — but watch the wizard's trick! **Step 1** — Find 10% of £40 by dividing by 10: that's £4. **Step 2** — Find 5% by halving the 10%: half of £4 is £2. **Step 3** — Add them: 15% = 10% + 5% = £4 + £2 = **£6**. That's the discount amount. **Step 4** — Subtract the discount from the original price: £40 − £6 = **£34**. So the jumper now costs £34. The wrinkle that trips people up is thinking the ANSWER is £6 — but £6 is only the money saved, not the new price! Always reread: the question asks for the new price, so you must subtract. Another safety check: £34 is less than £40, which is exactly what a discount should do. Building percentages from 10% (divide by 10) and 5% (half of that) means you never need to memorise awkward fractions. This 'anchor on 10%' method works for 15%, 25%, 30%, 35% and beyond. Practise it until it feels automatic! 🧠

Time for a real GL/CEM exam-style challenge. **Question:** A shop sells a bike for £120. It offers 20% off. VAT of 20% is then added to the sale price. What is the final price? **Options: A) £96 B) £115.20 C) £144 D) £120**. Let's work it through. First, 20% off £120: 10% of £120 is £12, so 20% is £24 discount. Sale price = £120 − £24 = **£96**. Next, add 20% VAT to £96: 10% of £96 is £9.60, so 20% is £19.20. Final price = £96 + £19.20 = **£115.20**, which is option B! Why are the distractors tempting? **A) £96** stops after the discount and forgets to add VAT. **C) £144** wrongly ADDS 20% to the full £120 without the discount. **D) £120** is the trap for someone who does nothing! The exam lesson: always do the discount FIRST, then VAT on the smaller amount, and check your answer against every option carefully. 🏆

Let's expose the three sneakiest mistakes that catch apprentices. **Mistake 1 — Writing £4.5 instead of £4.50.** This happens because pupils forget money always needs two decimal places. The fix: chant 'pence always take two seats!' — every money answer wears exactly two decimal digits. **Mistake 2 — Giving the discount amount as the final price.** A pupil finds £6 off a £40 jumper and writes £6 as the answer, when the price is actually £34. This happens from rushing and not rereading. The fix: after finding a discount, ask 'is this what I SAVED or what I PAY?' and subtract if it's the new price. **Mistake 3 — Muddling pounds and pence in subtraction.** When finding change from £5 for £3.72, pupils sometimes write £2.32 by subtracting carelessly. The fix: use the 'counting up' method — climb from the cost to a round pound, then up to the note. 🧙 The Wizard's #1 power tip for exam day: **anchor every percentage on 10%.** Divide by 10 to get 10%, then halve it for 5%, double it for 20%, and add pieces together for any percentage. This one trick turns terrifying discounts into gentle, quick additions. Master it, and money questions become your easiest marks of all! ✨

Common mistakes

• Wrong: £3.40 + £1.5 written as £4.90 — Right: £3.40 + £1.50 = £4.90 (write 1.50, not 1.5). Money always uses two decimal places — £1.5 means fifty pence, so write £1.50.
• Wrong: Change from £10 for £6.30 = £4.70 — Right: £10.00 − £6.30 = £3.70. Count up: £6.30 → £7 is 70p, → £10 is £3, so £3.70. Always check change is less than what you paid.
• Wrong: 20% off £50 = £10 (giving £10 as the price) — Right: 20% of £50 = £10 discount, so new price = £50 − £10 = £40. £10 is what you SAVE, not what you PAY. Reread: does it want the discount or the new price?
• Wrong: 15% of £80 = £15 — Right: 10% = £8, 5% = £4, so 15% = £8 + £4 = £12. Anchor on 10% (divide by 10), then build. Never guess percentages.
• Wrong: 20% off then 20% VAT on £120 → 20%−20% = 0% change, so £120 — Right: £120 − £24 (20% off) = £96; £96 + £19.20 (20% VAT) = £115.20. You can NEVER just subtract the percentages — they act on different amounts. Do discount first, then VAT on the smaller price.

Frequently asked questions

Why do we always need two numbers after the decimal point in money?

Because there are 100 pence in a pound! The two digits show the ten-pence and one-penny amounts. Writing £4.50 (not £4.5) makes it crystal clear you mean fifty pence. You're getting the hang of it! ⭐

What if I forget how to find a percentage in the exam?

Just anchor on 10% — divide the amount by 10. Then double it for 20%, halve it for 5%, or add pieces together. This one trick unlocks nearly every percentage. You've totally got this! 🧙

Do I do the discount or the VAT first?

Always the discount first! Subtract it to get the smaller sale price, THEN add VAT to that new amount. Doing them in this order keeps your treasure calculation correct every time. Great question! 🎯

What's the easiest way to work out change?

Count UP! Start at the cost, climb to the next round pound, then up to the note you paid. Add those jumps together. It's quicker and safer than subtracting. Give it a try — it feels like magic! ✨

Why does the exam try to trick us with the discount amount?

To check you read carefully! The saving and the new price are different numbers. Always ask: 'Do they want what I SAVED or what I PAY?' Spotting this earns you easy marks. You're thinking like a champion! 🏆

Will I really use this outside of school?

Absolutely — every time you shop, save pocket money, or check if a sale is a real bargain! Money maths is a skill for your whole life. Learning it now makes you super clever with cash. Keep going! 🧠