Albert Teen YOU ARE LEARNING:  What Are Percentages?  # What Are Percentages? ### What Are Percentages?

Percentages are a useful way to represent amounts. You can convert between fractions, decimals and percentages.

1

How many little blocks do you see here?  2

Now, how many of the blocks have been coloured in?  3

So $\frac{37}{100}$ blocks have been coloured in

This is the same as 37 percent of the blocks. How can you also write 37 percent? 1

What does "percent" $\%$ actually mean?

Where else do you know "cent" from? 2

How many centimetres are there in a metre?  3

How many years are there in a century?  4

How many centilitres are there in a litre?  5

So "percent" means "per _________".

A) $10$ B) $100$ C) $1000$  6

"Percent" means "per 100"

So when you say $37\%$, you actually say "37 out of 100" or $\frac{37}{100}$ 1

How many $\%$ of these blocks have been coloured in?  2

$\frac{50}{100}$ or $50\%$ of these blocks have been coloured in. What does the fraction $\frac{50}{100}$ become when it has been simplified as much as possible?  3

So $50\%$ is the same as $\frac{50}{100}$ which is the same as $\frac{1}{2}$

Half of these blocks are coloured in. 1

Now, which one of these cakes shows that only $50\%$ is left? Answer A, B or C.  2

Which cake shows that only $25\%$ is left? Answer A, B or C.  3

Which cake shows that $100\%$ is left? Answer A, B or C.  4

So what is $100\%$ the same as?

A) $1$ B) $100$ C) $0$  5

So $100\%$ is the same as $\frac{100}{100}$ or $1$ whole

$50\%$ is the same as $\frac{50}{100}$ or $\frac{1}{2}$

$25\%$ is the same as $\frac{25}{100}$ or $\frac{1}{4}$ 1

How much is left of this pizza in $\%$?  How much is $\frac{69}{100}$ as a $\%$? How do you write $24\%$ as a fully simplified fraction? 1

To recap! "Percent" means "per 100"

Here there are $\frac{37}{100}$ blocks filled in, so that is $37\%$ 2

$100\%$ is the same as $1$ whole

$\frac{75}{100}$ or $75\%$ is the same as $\frac{3}{4}$

$\frac{50}{100}$ or $50\%$ is the same as $\frac{1}{2}$

$\frac{25}{100}$ or $25\%$ is the same as $\frac{1}{4}$ 1

So $1\%$ is the same as $\frac{1}{100}$

You can also say 1 hundredth. 2

How many hundredths are in the decimal $0.43$?  3

How do you think you can write $0.43$ as a $\%$?  4

So you can also change decimals to $\%$

For example, $0.43$ is the same as $\frac{43}{100}$ which is the same as $43\%$ How would you write $0.87$ as a $\%$? Now, how much is $0.134$ in $\%$? 1

So what do you actually do when you change decimals into $\%$?

Have a good look at these examples again. 2

You change decimals into $\%$ by _____________ by $100$

A) dividing B) multiplying  3

You change decimals into $\%$ by multiplying by $100$

For example, $87\%$ is $\times100$ bigger than $0.87$ Now, what is $8\%$ as a decimal? Pick the 3 options below that are the same as $40\%$ What is $200\%$ the same as? Pick the 3 options below that are the same as $150\%$ 1

Summary! "Percent" means "per 100"

$100\%$ is the same as $1$ whole. 2

You can change between fractions, decimals and percent

For example, $25\%$ is the same as $\frac{25}{100}$ or $\frac{1}{4}$ which is also the same as $0.25$ 