True or False? To increase an amount by 20% , you could multiply the amount by the multiplier 1.2.

True. To increase an amount by 20% , you could multiply the amount by the multiplier 1.2.

How would you find the multiplier for decreasing an amount by 15% ?

To find the multiplier for decreasing an amount by 15% , you would subtract 15 from 100 and then divide by 100. A multiplier for a decreasing amount will always be less than 1 .

How would you find one number as a percentage of another number , for example 12 as a percentage of 80?

To find one number as a percentage of another number, divide the first number by the second number then multiply by 100 . E.g. To find 12 as a percentage of 80, divide 12 by 80 and then multiply by 100.

True or False? One option for the first step to find a percentage change is to divide by the amount after by the amount before .

True. You can find a percentage change by dividing the amount after by the amount before . This gives you the multiplier for the change.

What is a reverse percentage ?

A reverse percentage is when you are given the value after a percentage increase or decrease and need to find the original value before the change.

True or False? If a number has been increased by 20% , to find the original number you decrease the new number by 20% .

False. If a number has been increased by 20% , you can not find the original number by decreasing the new number by 20% . You would divide by 1.2.

If you are given the new number after a percentage increase or decrease, how do you find the original number?

Find the multiplier for the percentage change. Divide the new number by the multiplier .

What is the multiplier when a number has been increased by 25% ?

The multiplier for a 25% increase is 1.25 . Add 25 to 100 and then divide by 100.

True or False? A number has been decreased by 10% . To find the original number, multiply the new number by 0.9 .

False. A number has been decreased by 10% . To find the original number, divide the new number by 0.9 . Do not multiply .

True or False? A number has been increased by 20% . To find the original number, divide the new number by 0.2 .

False. A number has been increased by 20% . To find the original number, divide the new number by 1.2 , not 0.2. You need to add 20 to 100 and then divide by 100 to find the mutliplier.

IGCSEMaths A: HigherEdexcelFlashcards

Percentages (Edexcel IGCSE Maths A)

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What number is a percentage out of?

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What number is a percentage out of?
A percentage is out of 100.
True or False?
To find a percentage of an amount, you can divide the percentage by 100 and multiply by the amount.
True.
To find a percentage of an amount, you divide the percentage by 100 and multiply by the amount.
For example, 23% of 60 can be found by calculating $\frac{23}{100} \times 60$
True or False?
To increase an amount by 20%, you could multiply the amount by the multiplier 1.2.
True.
To increase an amount by 20%, you could multiply the amount by the multiplier 1.2.
How would you find the multiplier for decreasing an amount by 15%?
To find the multiplier for decreasing an amount by 15%, you would subtract 15 from 100 and then divide by 100.
A multiplier for a decreasing amount will always be less than 1.
How would you find one number as a percentage of another number, for example 12 as a percentage of 80?
To find one number as a percentage of another number, divide the first number by the second number then multiply by 100.
E.g. To find 12 as a percentage of 80, divide 12 by 80 and then multiply by 100.
True or False?
To find the percentage change from 20 to 32 you can calculate $\frac{32 - 20}{32} \times 100$ .
False.
To find a percentage change, you need to divide by the original number.
$\frac{32 - 20}{20} \times 100$
True or False?
One option for the first step to find a percentage change is to divide by the amount after by the amount before.
True.
You can find a percentage change by dividing the amount after by the amount before. This gives you the multiplier for the change.
What is a reverse percentage?
A reverse percentage is when you are given the value after a percentage increase or decrease and need to find the original value before the change.
True or False?
If a number has been increased by 20%, to find the original number you decrease the new number by 20%.
False.
If a number has been increased by 20%, you can not find the original number by decreasing the new number by 20%.
You would divide by 1.2.
If you are given the new number after a percentage increase or decrease, how do you find the original number?
Find the multiplier for the percentage change. Divide the new number by the multiplier.
What is the multiplier when a number has been increased by 25%?
The multiplier for a 25% increase is 1.25.
Add 25 to 100 and then divide by 100.
True or False?
A number has been decreased by 10%. To find the original number, multiply the new number by 0.9.
False.
A number has been decreased by 10%. To find the original number, divide the new number by 0.9. Do not multiply.
True or False?
A number has been increased by 20%. To find the original number, divide the new number by 0.2.
False.
A number has been increased by 20%. To find the original number, divide the new number by 1.2, not 0.2. You need to add 20 to 100 and then divide by 100 to find the mutliplier.

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