Ratio and Proportion

Post on 14-Nov-2014

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Transcript of Ratio and Proportion

Ratio and proportionRATIO compares part to part,

‘two to every three’ or ‘two for every three’

PROPORTION compares a part to the whole,

‘two out of five’ (this is like a fraction)

Ratio and proportionRATIO compares part to part,

‘two to every three’ or ‘two for every three’

What is the ratio of red to white?

What is the ratio of white to red?

Ratio and proportionRATIO compares part to part,

‘two to every three’ or ‘two for every three’

What is the ratio of red to white?

one red to every two white

What is the ratio of white to red?

two white to every one red

Ratio and proportionRATIO compares part to part,

‘two to every three’ or ‘two for every three’

What is the ratio of red to white?

one to two

What is the ratio of white to red?

two to one

Ratio and proportionRATIO compares part to part,

‘two to every three’ or ‘two for every three’

What is the ratio of red to white?

one to two

What is the ratio of white to red?

two to one

Ratio and proportionRATIO compares part to part,

‘two to every three’ or ‘two for every three’

What is the ratio of red to white?

1 to 2

What is the ratio of white to red?

2 to 1

Ratio and proportionRATIO compares part to part,

‘two to every three’ or ‘two for every three’

What is the ratio of red to white?

1 : 2

What is the ratio of white to red?

2 : 1

Ratio and proportionPROPORTION compares a part to the whole,

‘two in every five’ (this is like a fraction)

What proportion of this shape is red?

What proportion of this shape is white?

Ratio and proportionPROPORTION compares a part to the whole,

‘two in every five’ (this is like a fraction)

What proportion of this shape is red?

four reds out of twelve squares in total

What proportion of this shape is white?

eight whites out of twelve squares in total

Ratio and proportionPROPORTION compares a part to the whole,

‘two in every five’ (this is like a fraction)

What proportion of this shape is red?

four out of twelve

What proportion of this shape is white?

eight out of twelve

Ratio and proportionPROPORTION compares a part to the whole,

‘two in every five’ (this is like a fraction)

What proportion of this shape is red?

four / twelve

What proportion of this shape is white?

eight / twelve

Ratio and proportionPROPORTION compares a part to the whole,

‘two in every five’ (this is like a fraction)

What proportion of this shape is red?

4 / 12

What proportion of this shape is white?

8 / 12

Ratio and proportionPROPORTION compares a part to the whole,

‘two in every five’ (this is like a fraction)

What proportion of this shape is red?

What proportion of this shape is white?

4

12

8

12

Ratio and proportionPROPORTION compares a part to the whole,

‘two in every five’ (this is like a fraction)

What proportion of this shape is red?

What proportion of this shape is white?

4

12

8

12

1

3

2

3

Ratio and proportion – A SATs question

Mari is the presenter of a weekly radio show.

She plays five new songs for every two old songs. Last week she played 15 new songs. How many songs did she play altogether?

Ratio and proportion

Mari is the presenter of a weekly radio show.

She plays five new songs for every two old songs. Last week she played 15 new songs. How many songs did she play altogether?

Ratio and proportion

Mari is the presenter of a weekly radio show.

five new : two old15 new : ?

Ratio and proportion

Mari is the presenter of a weekly radio show.

5 new : 2 old15 new : ?

Ratio and proportion

Mari is the presenter of a weekly radio show.

5 : 2 15 : ?

Ratio and proportion

Mari is the presenter of a weekly radio show.

5 : 2 15 : ?

X 3

Ratio and proportion

Mari is the presenter of a weekly radio show.

5 : 2 15 : 6

X 3 X 3

Ratio and proportion

Mari is the presenter of a weekly radio show.

How many songs did she play altogether?

She played 6 old songs and 15 new songs.

Ratio and proportion

Mari is the presenter of a weekly radio show.

How many songs did she play altogether?

She played 21 songs altogether.

Ratio and proportion – Another SATs question

Here is a recipe for raspberry ice cream.

This recipe is for 8 people. Josie makes enough raspberry ice cream for 12 people. How much cream does she use?

Fred makes raspberry ice cream in the same way. He uses 2½ kg of raspberries. How much sugar does he use?