Part of Application of number (Levels 1 and 2)Learn the basics
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Speaker: Percentages are everywhere.
Percent means 'out of 100'. 100% means the whole amount and the symbol you use that means percent looks like this. (%)
When you have 50 out of 100 that is 50%.
When you have 25% that's 25 out of 100.
So 100 out of 100 is 100%.
But it's important to remember that the whole will not always be 100 things.
I have 6 eggs in my 6-egg carton so I have 100%.
Half of 100% is 50%, so 50% of my eggs would be half of the 6. That's 3 eggs.
20% is the same as 20 out of 100 and you can always write a percentage as a fraction.
63% is 63 out of 100 or 63 hundredths.
Test your knowledge with this activity.
Speaker: We come across percentages a lot in everyday life.
They're often used when shops have sales or offers on.
The full price of this canvas is 拢10.
But I need to know what 30% off is.
So, 1% is one hundredth of the whole price.
So 30% is 30 times that.
If my 100% is 拢10, then 1% is 拢10 divided by 100, which is 10 pence.
But I need to know what 30% is. So I multiply my 10p by 30, and I get 拢3.00.
I need to remember to take the 拢3 from the 拢10, so the canvas will cost me 拢7.00.
And if I check it with a calculator, I divide 30 by 100 first because 30% is 30 out of 100.
That gives me 0.3. I multiply 0.3 by 10 which is鈥 拢3.00. 10 minus 3 is 7.
Speaker: Working out 20% or 30% of something is one thing, but what if you need to work out something a bit trickier?
I need to get 75 marks out of a possible 120 on my exam paper to pass the module.
I want to work out what that is as a percentage.
So I need to work out what fraction 75 is of 120.
That's 75 divided by 120, so that's 0.625 and I know, to turn a decimal fraction into a percentage, I just multiply by 100.
So, I need to get at least 62.5%.
That's OK, I'm on my way there already.
I'm going to aim higher than that.
Find out more by working through a topic
Decimal numbers and the decimal point
Addition and use of the column method
Subtracting numbers using the column and chunking method
Multiplication using the grid method and repeated addition