This document defines ratio and proportion. A ratio compares parts to parts and is written with a colon, such as 1:2. A proportion compares a part to the whole and is written as a fraction, such as 1/3. An example is provided of using a ratio to solve a word problem about the number of new and old songs played on a radio show given the number of new songs.

1. 
RATIO AND
PROPORTIONSBY: MARK G. E. AQUINO

2. 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)

3. 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?

4. 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

5. 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

6. 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

7. 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

8. 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?

9. 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

10. 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

11. 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

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

13. 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?
4
12
8
12

14. 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?
4
12
8
12
1
3
2
3

15. 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?

16. 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?

17. Ratio and proportion
Mari is the presenter of a weekly radio show.
five new : two old
15 new : ?

18. Ratio and proportion
Mari is the presenter of a weekly radio show.
5 new : 2 old
15 new : ?

19. Ratio and proportion
Mari is the presenter of a weekly radio show.
5 : 2
15 : ?

20. Ratio and proportion
Mari is the presenter of a weekly radio show.
5 : 2
15 : ?
X 3

21. Ratio and proportion
Mari is the presenter of a weekly radio show.
5 : 2
15 : 6
X 3 X 3

22. 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.

23. Ratio and proportion
Mari is the presenter of a weekly radio show.
How many songs did she play altogether?
She played 21 songs altogether.

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THANK
YOU