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)
Ratio and proportion
RATIO 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 proportion
RATIO 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 proportion
RATIO 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 proportion
RATIO 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 proportion
RATIO 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 proportion
RATIO 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 proportion
PROPORTION 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 proportion
PROPORTION 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 proportion
PROPORTION 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 proportion
PROPORTION 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 proportion
PROPORTION 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 proportion
PROPORTION 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 proportion
PROPORTION compares a part to the whole,
‘two in every five’ (this is like a fraction)
What proportion of this shape is red?
4
1
12
3
What proportion of this shape is white?
8
2
12
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
15 new
:
:
two old
?
Ratio and proportion
Mari is the presenter of a weekly radio show.
5 new
15 new
:
:
2 old
?
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
X3
15 : ?
Ratio and proportion
Mari is the presenter of a weekly radio show.
5:2
X3
15 : 6
X3
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?