Ratio and Proportion

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Ratio and proportion RATIO 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)

Transcript of Ratio and Proportion

Page 1: 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)

Page 2: Ratio and Proportion

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?

Page 3: Ratio and Proportion

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

Page 4: Ratio and Proportion

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

Page 5: Ratio and Proportion

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

Page 6: Ratio and Proportion

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

Page 7: Ratio and Proportion

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

Page 8: Ratio and Proportion

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?

Page 9: Ratio and Proportion

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

Page 10: Ratio and Proportion

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

Page 11: Ratio and Proportion

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

Page 12: Ratio and Proportion

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

Page 13: Ratio and Proportion

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

Page 14: Ratio and Proportion

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

Page 15: Ratio and Proportion

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?

Page 16: Ratio and Proportion

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?

Page 17: Ratio and Proportion

Ratio and proportion

Mari is the presenter of a weekly radio show.

five new : two old15 new : ?

Page 18: Ratio and Proportion

Ratio and proportion

Mari is the presenter of a weekly radio show.

5 new : 2 old15 new : ?

Page 19: Ratio and Proportion

Ratio and proportion

Mari is the presenter of a weekly radio show.

5 : 2 15 : ?

Page 20: Ratio and Proportion

Ratio and proportion

Mari is the presenter of a weekly radio show.

5 : 2 15 : ?

X 3

Page 21: Ratio and Proportion

Ratio and proportion

Mari is the presenter of a weekly radio show.

5 : 2 15 : 6

X 3 X 3

Page 22: Ratio and Proportion

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.

Page 23: Ratio and Proportion

Ratio and proportion

Mari is the presenter of a weekly radio show.

How many songs did she play altogether?

She played 21 songs altogether.

Page 24: Ratio and Proportion

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?