Slide 1Copyright © 2015, 2011, 2008 Pearson Education, Inc.

Weight and Mass

Section 9.5

Slide 2Copyright © 2015, 2011, 2008 Pearson Education, Inc.

Defining and Converting U.S. System Units of Weight

When we talk about how heavy an object is, we are concerned with the object’s weight.

The most common units of weight in the U.S. measurement system are the ounce, the pound, and the ton.

Slide 3Copyright © 2015, 2011, 2008 Pearson Education, Inc.

Defining and Converting Metric System Units of Length

U.S. Units of Weight Unit Fractions16 ounces (oz) = 1 pound (lb)

2000 pounds = 1 ton

16 oz 1 lb1

1 lb 16 oz

2000 lb 1 ton1

1 ton 2000 lb

Slide 4Copyright © 2015, 2011, 2008 Pearson Education, Inc.

Example

Convert 9000 pounds to tons.

Slide 5Copyright © 2015, 2011, 2008 Pearson Education, Inc.

Example

Convert 5 pounds to ounces.

Slide 6Copyright © 2015, 2011, 2008 Pearson Education, Inc.

ExampleConvert: 38 ounces = ____ lb ____ oz

Slide 7Copyright © 2015, 2011, 2008 Pearson Education, Inc.

Example

Subtract 3 tons 1295 pounds from 7 pounds 1000 lb

Slide 8Copyright © 2015, 2011, 2008 Pearson Education, Inc.

Defining and Converting Metric System Units of Mass

Metric Units of Mass

1 kilogram (kg) = 1000 grams (g)

1 hectogram (hg) = 100 g

1 dekagram (dag) = 10 g

1 gram = 1g

1 decigram (dg) = 1/10 or 0.1 g

1 centigram (cg) = 1/100 g or 0.01 g

1 milligram (mg) = 1/1000 or 0.001 g

Slide 9Copyright © 2015, 2011, 2008 Pearson Education, Inc.

Defining and Converting Metric System Units of Length

A large paper clip weighs approximately 1 gram.

A box of crackers weights 453 grams.

A kilogram is slightly over 2 pounds.

Slide 10Copyright © 2015, 2011, 2008 Pearson Education, Inc.

Example

Convert 360,000 mg to grams.

List the units of length in order from left to right and move from milligrams to grams.

kg hg dag g dg cg mg

Move the decimal point three units to the left.

360,000 mg = 360.000 g or 360 g

3 units to the left

Slide 11Copyright © 2015, 2011, 2008 Pearson Education, Inc.

Example

Subtract 3.1 dg from 2.5 g.