What are fractions?

10 out of 100

As you have seen on the first page of this presentation Fractions can be shown in many different ways.

Fractions help us to represent PARTS of something. They are very important. Without them we would have difficulty explaining how much of the drink is left in this glass, or how much pizza each person will get.

You will usually see fractions that look like this. One number sitting on top of another number with a line in the middle. Do you know what these two numbers mean?

The TOP number tells us how many PARTS of something we have selected.

The BOTTOM number tells us how many PARTS there should be altogether to make up a whole.

3 of the squares are pink.

There are 4 squares all together

3 out of the 4 squares are pink. We write it this way:

Of the squares are pink.

Try these examples yourself!

Top number = how many parts you have (These are shaded yellow)

Bottom number = how many parts there are ALL TOGETHER.

Web Quest Log Book Activity

In your log book create some of your own fractions challenges for other students. It doesn’t matter what shape your fractions are or how they are arranged. The important thing is that it is easy to see which parts are selected and how many parts there are all together.

Present your work neatly and use colour pencils or textas to improve your presentation. You might like to work on the computer and then print out your work to stick into your journal.

Fractions can also show parts of other things – like a line !

The top number shows that this point is the end of the FIRST section.

The bottom number tells us how many parts the line is broken into ALL TOGETHER.

1 2 3 4 5 6 7

This line is broken into 7 EQUAL parts

Remember – the TOP number tells us where each section ends. e.g. the First section,

Second Section, Third section etc.

The BOTTOM number tells us how many sections there are ALL TOGETHER

Sometimes different fractions can mean the same thing.

Show the same point in the line.

and

They mean the same thing – they are equivalent fractions !

Equivalent fractions can look like this too.

5 parts out of ten is the same as one part out of 2.

Do you think this is always the case? Try drawing some examples in your log book to see. Remember – the parts

must always be divided evenly. Each section must be exactly the same as the others. How many other equivalent

fractions can you find?

Different looking fractions.

We have discovered that fractions are a way of showing PARTS of things. What would we do if we wanted to show a part of the number one?

Instead we need a way of showing smaller numbers than ONE. A way of showing a PART of the number one.

We do this by breaking the whole number ONE into smaller parts.

It wouldn’t make sense to chop the number in

half !

Tenths

One WHOLE part can be broken into 10 equal parts.

We use the number 1 to show one whole.

10 parts out of 10 makes One Whole.

One part out of ten is written as

5 parts out of 10 is written as

HundredthsWhole numbers

can also be broken up into

100 parts.

What fraction of these squares are

shaded? (Remember the top

number tells us how many are

shaded and the bottom number

tells us how many altogether)

Tenths and hundredths can be written as decimal numbers.

Hundreds Tens Units Just like whole numbers can be represented in columns so can parts of whole numbers.

Units Tenths Hundredths

Part of 10

Part of 100

The decimal point shows the difference between whole numbers and parts of whole numbers. The whole numbers are on the LEFT side of the decimal point.

Writing tenths and hundredths as decimals.

Units Tenths

1 Part of 10

Hundredths

Units Tenths

1

Hundredths

One part out of ten is written as

0

10Can be written as

Writing tenths and hundredths as decimals.

Units Tenths

5 Parts out of 10

Hundredths

Units Tenths

5

Hundredths

Five parts out of ten is written as

0

50Can be written as

Writing tenths and hundredths as decimals.

Units Tenths

5 Parts out of 100

Hundredths

Units Tenths

5

Hundredths Five parts out of one hundred (five hundredths) is written as

0

00Can be written as

0

5

Another name for parts out of 100

% This sign is the percentage sign – it means

“ out of 100”

54% means 54 out of 100.

Do you remember when we talked about fractions? They also show a part out of a total number of parts. This percentage sign tells us that the total number of parts is 100.

Press the space bar to see the computer represent 20 % (That 20 out of – you guessed it! – 100)