Conversions

Your first conversion!!

Convert your age in years to seconds.

In science, it is often usefulto 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?

First we will see how it works with dozen.

You know that a dozen is 12 of something.

If you have 36 donuts,how many dozen donuts do you have?

You want to know how many dozen in 36 donuts,and you know there is 1 dozen per 12 donuts, or 1 dozen12 donuts

Use this relationship to convert fromindividual donuts to dozen donuts:

36 donuts x 1 dozen12 donuts

In the problem how many dozen in 36 donuts,you know there is 1 dozen per 12 donuts, or 1 dozen12 donuts

Use this relationship to convert fromindividual donuts to dozen donuts:

In the problem how many dozen in 36 donuts,you know there is 1 dozen per 12 donuts, or 1 dozen12 donuts

36 donuts x = 1 dozen12 donuts

36 donuts x 1 dozen 12 donuts

Use this relationship to convert fromindividual donuts to dozen donuts:

In the problem how many dozen in 36 donuts,you know there is 1 dozen per 12 donuts, or 1 dozen12 donuts

36 donuts x = 1 dozen12 donuts

36 donuts x 1 dozen 12 donuts

= 36 dozen 12

Use this relationship to convert fromindividual donuts to dozen donuts:

In the problem how many dozen in 36 donuts,you know there is 1 dozen per 12 donuts, or 1 dozen12 donuts

36 donuts x = 1 dozen12 donuts

36 donuts x 1 dozen 12 donuts

= 36 dozen 12

= 3 dozen

Use this relationship to convert fromindividual donuts to dozen donuts:

In the problem how many dozen in 36 donuts,you know there is 1 dozen per 12 donuts, or 1 dozen12 donuts

36 donuts x = 1 dozen12 donuts

36 donuts x 1 dozen 12 donuts

= 36 dozen 12

= 3 dozen

Use this relationship to convert fromindividual donuts to dozen donuts:

= 3 dozen36 donuts

If you have 2.5 dozen donuts, how many individualdonuts are there?

2.5 dozen x 12 donuts1 dozen

there are 12 donutsin 1 dozen

If you have 2.5 dozen donuts, how many individualdonuts are there?

2.5 dozen x =12 donuts1 dozen

2.5 dozen x 12 donuts1 dozen

2.5 x 12 donuts1

=

= 30 donuts

Here are the two problems side by side:

2.5 dozen 12 donuts 2.5 dozen x 12 donuts1 dozen 1 dozen

2.5 x 12 donuts 1

30 donuts

x =

=

=

x =36 donuts 1 dozen 36 donuts 1 dozen12 donuts 12 donuts

36 dozen 1

3 dozen

=

=

x

notice the two conversion factorsare reciprocals of each other

2

2.5 dozen 12 donuts 2.5 dozen x 12 donuts1 dozen 1 dozen

2.5 x 12 donuts 1

30 donuts

x =

=

=

x =36 donuts 1 dozen 36 donuts 1 dozen12 donuts 12 donuts

36 dozen 1

3 dozen

=

=

x

12 donuts = 1 dozen

1 dozen12 donuts = 1

12 donuts 1 dozen = 1

2.5 dozen 12 donuts 2.5 dozen x 12 donuts1 dozen 1 dozen

2.5 x 12 donuts 1

30 donuts

x =

=

=

x =36 donuts 1 dozen 36 donuts 1 dozen12 donuts 12 donuts

36 dozen 1

3 dozen

=

=

x

12 donuts = 1 dozen

1 dozen12 donuts

12 donuts 1 dozen = 1

= 1converts

donuts to dozen

2.5 dozen 12 donuts 2.5 dozen x 12 donuts1 dozen 1 dozen

2.5 x 12 donuts 1

30 donuts

x =

=

=

x =36 donuts 1 dozen 36 donuts 1 dozen12 donuts 12 donuts

36 dozen 1

3 dozen

=

=

x

12 donuts = 1 dozen

1 dozen12 donuts

12 donuts 1 dozen = 1

= 1converts

dozen to donuts

Since conversion factors always equal 1,you can multiply them by anything you

want and still end up with the same thingexcept that it will be in a different form.

!!!REMEMBER!!! You are changing the form of the number not the value.

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

If you have 9900 grams of donuts,how many donuts do you have

if each donut has a mass of 150 grams?

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?

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?

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?

grams to donuts

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

If you have 9900 grams of donuts,how many donuts do you have

if each donut has a mass of 150 grams?

3. set up the conversion factors:

150 g = 1 donut

so…

and

150 g1 donut

= 1

1 donut150 g = 1

150 g = 1 donut

150 g1 donut

= 1

1 donut150 g = 1

these are yourconversion factors

150 g = 1 donut

150 g1 donut

= 1

1 donut150 g = 1

converts donuts tograms (grams on top)

150 g = 1 donut

150 g1 donut

= 1

1 donut150 g = 1

converts grams todonuts (donuts on top)

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?

The question is…

9900 grams

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 amountgiven 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 gram s

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 gram s

each donut has a mass of 150 grams

The question is…

x9900 gram s 1 donut150 grams

converts gramsto donuts

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

The question is…

x9900 gram s 1 donut150 grams

If you have 9900 grams of donuts,how many donuts do you have

if each donut has a mass of 150 grams?

9900 donuts 150

66 donuts

=

= 66 donuts

The question is…

x9900 gram s 1 donut150 grams

x=

9900 g 1 donut150 g

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

9900 gram s = 66 donuts

What if it’s not donuts?

•You have to know the relationship!!

English

• 1ft. = 12in

• 3ft. = 1 yd

• 5280ft. = 1mile

• What are the conversion factors?

Metric Relationships•King Henry Died By Drinking Chocolate Milk

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 = 2.205 lb

• 1 lb = 453.6 g

• 1 lb = 16 oz

• 1 L = 1.06 qt

Now for some practice!!!