1. Conversions

2. Convert your age in years to seconds.
Your first conversion!!
Convert your age in years to seconds.

3. In science, it is often useful to be able to convert from one
unit of measure to another
For example:
If you have 24 students in a class and you want to give each student 4 cookies, how many dozen do you need?

4. First we will see how it works with dozen.

5. You know that a dozen is 12 of something.
If you have 36 donuts,
how many dozen donuts do you have?

6. You want to know how many dozen in 36 donuts,
and you know there is 1 dozen per 12 donuts, or
1 dozen
Use this relationship to convert from
individual donuts to dozen donuts:
12 donuts

7. In the problem how many dozen in 36 donuts,
you know there is 1 dozen per 12 donuts, or
1 dozen
Use this relationship to convert from
individual donuts to dozen donuts:
12 donuts
36 donuts x
1 dozen
12 donuts

8. In the problem how many dozen in 36 donuts,
you know there is 1 dozen per 12 donuts, or
1 dozen
Use this relationship to convert from
individual donuts to dozen donuts:
12 donuts
1 dozen
12 donuts
36 donuts x 1 dozen
12 donuts
36 donuts x =

9. In the problem how many dozen in 36 donuts,
you know there is 1 dozen per 12 donuts, or
1 dozen
Use this relationship to convert from
individual donuts to dozen donuts:
12 donuts
1 dozen
12 donuts
36 donuts x 1 dozen
12 donuts
36 donuts x = =
36 dozen 12

10. In the problem how many dozen in 36 donuts,
you know there is 1 dozen per 12 donuts, or
1 dozen
Use this relationship to convert from
individual donuts to dozen donuts:
12 donuts
1 dozen
12 donuts
36 donuts x 1 dozen
12 donuts
36 donuts x = =
36 dozen 12 =
3 dozen

11. In the problem how many dozen in 36 donuts,
you know there is 1 dozen per 12 donuts, or
1 dozen
Use this relationship to convert from
individual donuts to dozen donuts:
12 donuts
1 dozen
12 donuts
36 donuts x 1 dozen
12 donuts
36 donuts x = =
36 dozen 12 =
3 dozen

12. 36 donuts =
3 dozen

13. If you have 2.5 dozen donuts, how many individual
donuts are there?
there are 12 donuts
in 1 dozen
2.5 dozen x
12 donuts
1 dozen

14. If you have 2.5 dozen donuts, how many individual
donuts are there?
12 donuts
2.5 dozen x 12 donuts
1 dozen
2.5 dozen x =
1 dozen
2.5 x 12 donuts 1 = =
30 donuts

15. notice the two conversion factors are reciprocals of each other
Here are the two problems side by side:
notice the two conversion factors
are reciprocals of each other 2

16. 12 donuts = 1 dozen
12 donuts
1 dozen
= 1
1 dozen
12 donuts
= 1

17. = 1 converts donuts to dozen = 1 12 donuts = 1 dozen 12 donuts 1 dozen

18. = 1 converts dozen to donuts = 1 12 donuts = 1 dozen 12 donuts 1 dozen

19. Since conversion factors always equal 1,
you can multiply them by anything you
want and still end up with the same thing
except that it will be in a different form.
!!!REMEMBER!!! You are changing the form of the number not the value.

20. Let’s try converting donut mass to
number of donuts…

21. If you have 9900 grams of donuts, how many donuts do you have
if each donut has a mass of 150 grams?

22. What’s the conversion? If you have 9900 grams of donuts,
how many donuts do you have
if each donut has a mass of 150 grams?
What’s the conversion?

23. 1. what is the question asking you to convert?
If you have 9900 grams of donuts,
how many donuts do you have
if each donut has a mass of 150 grams?
1. what is the question asking you to convert?

24. grams to donuts 1. what is the question asking you to convert?
If you have 9900 grams of donuts,
how many donuts do you have
if each donut has a mass of 150 grams?
1. what is the question asking you to convert?
grams to donuts

25. 2. what is the relationship between grams and donuts?
If you have 9900 grams of donuts,
how many donuts do you have
if each donut has a mass of 150 grams?
2. what is the relationship between grams and donuts?

26. 2. what is the relationship between grams and donuts?
If you have 9900 grams of donuts,
how many donuts do you have
if each donut has a mass of 150 grams?
2. what is the relationship between grams and donuts?
150 grams = 1 donut

27. 3. set up the conversion factors:

28. 150 g = 1 donut
so…
150 g
1 donut
= 1
and
1 donut
150 g
= 1

29. 150 g = 1 donut
150 g
1 donut
= 1
these are your
conversion factors
1 donut
150 g
= 1

30. 150 g = 1 donut 150 g = 1 1 donut 1 donut 150 g = 1 converts donuts to
grams (grams on top)
1 donut
150 g
= 1

31. 150 g = 1 donut 150 g = 1 1 donut 1 donut 150 g = 1 converts grams to
donuts (donuts on top)
1 donut
150 g
= 1

32. If you have 9900 grams of donuts, how many donuts do you have
The question is…
If you have 9900 grams of donuts,
how many donuts do you have
if each donut has a mass of 150 grams?

33. begin with the amount given in the problem
The question is…
If you have 9900 grams of donuts,
how many donuts do you have
if each donut has a mass of 150 grams?
9900 grams
begin with the amount
given in the problem

34. If you have 9900 grams of donuts, how many donuts do you have
The question is…
If you have 9900 grams of donuts,
how many donuts do you have
if each donut has a mass of 150 grams?

35. If you have 9900 grams of donuts, how many donuts do you have
The question is…
If you have 9900 grams of donuts,
how many donuts do you have
if each donut has a mass of 150 grams?
each donut has a mass of 150 grams

36. converts grams to donuts
The question is…
If you have 9900 grams of donuts,
how many donuts do you have
if each donut has a mass of 150 grams?
each donut has a mass of 150 grams
converts grams
to donuts

37. If you have 9900 grams of donuts, how many donuts do you have
The question is…
If you have 9900 grams of donuts,
how many donuts do you have
if each donut has a mass of 150 grams?

38. If you have 9900 grams of donuts, how many donuts do you have
The question is…
If you have 9900 grams of donuts,
how many donuts do you have
if each donut has a mass of 150 grams?
how many donuts do you have

39. =

40. What if it’s not donuts?
You have to know the relationship!!

41. English 1ft. = 12in 3ft. = 1 yd 5280ft. = 1mile
What are the conversion factors?

42. Metric Relationships
King Henry Died By Drinking Chocolate Milk

43. Common conversions 2.54 cm = 1 in 4 qt = 1 gallon
5280 ft = 1 mile 4 cups = 48 tsp
2000 lb = 1 ton
1 kg = lb
1 lb = g
1 lb = 16 oz
1 L = 1.06 qt

44. Now for some practice!!!