2. L E A R N I N G I N T E N T I O N S
• Understand what the term ' percent' means
• Understand the 2-step method for finding percentages of an
amount.
• Increase and decrease amounts by a given percentage
• Write percentages of an amount using knowledge of fractions
and conversions
3. P E RC E N TAG E O F A N A M O U N T
If we know that percentage is always out of 100, we can write percentages as
fractions.
Eg. 15% of 60 = 15
/100 of 60
Now use your knowledge of fractions to work out the answer
60 ÷ 100 x 15 = 9
4. P E RC E N TAG E O F A N A M O U N T
Think of the percentage as a fraction (divide by bottom, times by top)
Find 66% of 78
78 ÷ 100 x 66 = 51.48
Find 45% of 950
950 ÷ 100 x 45 = 427.5
5. P E RC E N TAG E O F A N A M O U N T O N A C A L C U L AT O R
Another way of working out percentages is to use your calculator and
multiply
Find 66% of 78
66% x 78 = 51.48
Find 45% of 950
45% x 950 = 427.5
On the CASIO calculators,
press the 'catalogue'
button and select
'probability' to find the
percentage sign
6. P E RC E N TAG E O F A N A M O U N T O N A C A L C U L AT O R
Practice both methods on the following calculations:
1. 13% of 500 6. 24% of 1400
2. 12% of 800 7. 32% of 800
3. 23% of 600 8. 38% of 1300
4. 26% of 700 9. 31% of 300
5. 28% of 900 10. 35% of 600
8. I N C R E A S E V S D E C R E A S E
Increase means
the size or
amount of
something goes
UP or gets
BIGGER
Decrease means the
amount of
something goes
DOWN or gets
SMALLER
Words that suggest something
is getting bigger:
Increase
Rise
Grow
Tax
VAT
Words that suggest something
is getting smaller:
Decrease
Lower
Drop
Discount
Sale
9. P E RC E N TAG E I N C R E A S E
Find the percentage of the amount using one of the methods from earlier.
In these examples, we are looking at an increase, so ADD your answer to
the first step from the original amount in the question
A bottle of shampoo is £22.50 excluding VAT. If VAT is 20%, what should the
price be including VAT?
10. P E RC E N TAG E I N C R E A S E
Find the percentage of the amount using one of the methods from earlier.
In these examples, we are looking at an increase, so ADD your answer to
the first step from the original amount in the question
A jar of coffee which is normally 500g is advertised as being 'Special Edition
– 35% extra'. How much coffee is in the jar?
11. P E RC E N TAG E D E C R E A S E
Find the percentage of the amount using one of the methods from earlier.
In these examples, we are looking at an decrease, so TAKE AWAY your
answer from to the first step from the original amount in the question
A bar is selling drinks on offer 'Buy two, get the third 25% off'. If the drinks
cost £4.80, how much is the third drink?
12. P E RC E N TAG E D E C R E A S E
Find the percentage of the amount using one of the methods from earlier.
In these examples, we are looking at an decrease, so TAKE AWAY your
answer from to the first step from the original amount in the question
A bill for restyles and foils for two bridesmaids comes to £220. The
customer has a voucher for 10% discount. How much is the discount and
what is the new price?
10% of £220 = £22 (discount)
£220 - £22 = £198 (new price)
13. Q U I Z T I M E
https://wordwall.net/play/88079/682/
604
14. W R I T I N G P E RC E N TAG E S O F A N A M O U N T
1. Write the number as a fraction first.
2. Convert the fraction into a percentage (top ÷ bottom x 100)
Eg. You are collecting data in your salon, you find that in one day, you had
44 clients and 11 of those were male. What percentage were male?
11
/44
11 ÷ 44 x 100 = 25%
15. W R I T I N G P E RC E N TAG E S O F A N A M O U N T
Write the number as a fraction first – Remember the total (bigger) number
always goes on the bottom.
Convert the fraction into a percentage (top ÷ bottom x 100)
Eg. You have started a mobile catering company and want to advertise in the
local newspaper. An advert usually costs £80 but they have agreed to do it for
£32 because you are a new business. What percentage did you save?
Step 1: How much did you save?
Step 2: Write as a fraction 48
/80 (80 was the total price originally)
Step 3: Convert to a percentage 48 ÷ 80 x 100 = 25%
17. R E M E M B E R
Top ÷ bottom x 100
% over 100
simplify
÷ 100
18. L E A R N I N G I N T E N T I O N S
• Understand what the term ' percent' means
• Understand the 2-step method for finding percentages of an
amount.
• Increase and decrease amounts by a given percentage
• Write percentages of an amount using knowledge of fractions
and conversions
19. A N S W E R S
Slide 6: 1. 65 6. 336
2. 96 7. 256
3. 138 8. 494
4. 182 9. 93
5. 252 10. 210
20. A N S W E R S
Slide 9:
Slide 10:
Slide 11:
Slide 12:
20% of £22.50 = £4.50
£22.50 + £4.50 = £27
35% of 500g = 175g
500g + 175g = 675g
25% of £4.80 = £1.20
£4.80 - £1.20 = £3.60
10% of £220 = £22 (discount)
£220 - £22 = £198 (new price)
