Calculating new values after a percentage increase or decrease, understanding the difference between finding % of and increasing/decreasing by %.
Where your child meets this in real life: Calculating sale prices, price rises, population changes, or interest
SEAGReady breaks percentage increase and decrease into 3 steps, taught in order so each skill builds on the last.
Master percentage increase skills
Master percentage decrease skills
Master finding percentage vs changing by percentage skills
Three free sample questions from our percentage increase and decrease course. Every question comes with a full explanation, and hints that guide without giving the answer away.
A book costs £30. The price increases by 10%. What is the new price?
Answer: A. £33
Step 1: Find 10% of £30 10% = £30 ÷ 10 = £3 Step 2: Increase means ADD to the original £30 + £3 = £33 The new price is £33.
Stuck? Start here: First, find 10% of £30. What is £30 divided by 10?
A coat costs £80 and has 25% off in a sale. What is the sale price?
Answer: A. £60
Step 1: Find 25% of £80 25% = £80 ÷ 4 = £20 Step 2: Decrease means SUBTRACT £80 - £20 = £60 The sale price is £60.
Stuck? Start here: 25% is the same as one quarter. What is a quarter of £80?
Declan has £60 in savings. The bank adds 10% interest. How much does Declan have now?
Answer: A. £66
Step 1: Find 10% of £60 (the interest) 10% = £60 ÷ 10 = £6 Step 2: Interest is ADDED to savings £60 + £6 = £66 Declan has £66 in total.
Stuck? Start here: First find 10% of £60: divide by 10.
This is the exact interactive worked example your child sees in SEAGReady. Step through it and watch the method build up.
A jumper costs £40. The shop increases the price by 20% for the new season.
What is the new price of the jumper?
£40 + 20% of £40
Step 1 of 4
A jumper costs £40. The shop increases the price by 20% for the new season.
What is the new price of the jumper?
The new price of the jumper is £48.
The key insight: Percentage increase means finding the percentage and ADDING it to the original!
Watch out: 20% of £40 = £8, so the answer is £8. That's only the increase amount. You need to ADD it to the original price.
These are the misconceptions we see most often in percentage increase and decrease, including the ones our practice questions are specifically designed to catch.
Struggling with percentage increase and decrease? The real gap is often in one of these earlier topics.
SEAGReady finds the exact step where your child gets stuck, teaches it with worked examples like the one above, and brings it back for review so it sticks.