Slide 1

Do Now Complete the handout you picked up from the front door. Put HW to be checked on desk. Put tonights HW in HW folder. Write tonights HW in your agenda. Get out your ruler and binder to take notes. Slide 2 Metric System Unit 1 Day 3 Greeter: Read todays objectives Slide 3 DID YOU KNOW Its a metric world The united states is the only western country not presently using the metric system as its primary system of measurement. The only other countries in the world not using metric system as their primary system of measurement are Yemen, Brunei, and a few small islands; see Fig. 8.15. Slide 4 DID YOU KNOW In 1906, there was a major effort to convert to the metric system in the United States, but it was opposed by big business and the attempt failed. The Trade Act of 1988 and other legislation declare the metric system the preferred system of weights and measures of the U.S. trade and commerce, call for the federal government to adopt metric specifications, and mandate the Commerce Department to oversee the program. The conversion is currently under way; however, the metric system has not become the system of choice for most Americans daily use. Slide 5 DID YOU KNOW Lost in space In September 1999, the United States lost the Mars Climate Orbiter as it approached Mars. The loss of the $125 million spacecraft was due to scientists confusing English units and metric units. Two spacecraft teams, one at NASAs Jet Propulsion Lab (JPL) in Pasadena, CA, and the other at a Lockheed Martin facility in Colorado, where the spacecraft was built, were unknowingly exchanging some vital information in different units. The missing Mars Climate Orbiter Slide 6 American vs. Metric Length American standard 1 mile = 1760 yards = (5280 feet) 1 yard = 3 feet 1 foot = 12 inches 1 mil = 1 / 1,000 inch Metric standard 1 kilometer = 1000 meters 1 meter = 10 decimeters 1 decimeter = 10 centimeters ( 1 meter = 100 centimeters) 1 centimeter = 10 millimeters Conversion: 1 inch is defined to be exactly 2.54 cm in July, 1959. Slide 7 Metric System The metric system is based on a base unit that corresponds to a certain kind of measurement Length = meter Volume = liter Weight (Mass) = gram Temperature = celsius Slide 8 Metric System The units of the metric system are made up of prefixes and base units. Example: centi + meter = centimeter Example: kilo + gram = kilogram 8 PrefixBase Unit Slide 9 How to remember different lengths in the metric system: When you think of a millimeter (mm) think of: The thickness of a dime. When you think of a centimeter (cm) think of: The width of your pinky. Slide 10 How to remember different lengths in the metric system: When you think of a meter (m) think of: The height of the doorknob. When you think of a kilometer (km) think of: A little more than half of a mile Slide 11 Metric System The three prefixes that we will use the most are: kilo centi milli Slide 12 How can you remember these??? King Henry Died by Drinking Chocolate Milk King: Kilo Henry: Hecto Died: Deca By: Base (m, L, g) Drinking: Deci Chocolate: Centi Milk: Milli Slide 13 Metric System Centimeters are 10 times larger than millimeters so it takes more millimeters for the same length 1 centimeter = 10 millimeters Example not to scale 1 cm 40 41 40 Slide 14 Metric System An easy way to move within the metric system is by moving the decimal point one place for each step desired Example: change meters to centimeters 1 meter = 10 decimeters = 100 centimeters or 1.00 meter = 10.0 decimeters = 100. centimeters Slide 15 Metric System Now let s try our previous example from meters to kilometers: 16093 meters = 1609.3 decameters = 160.93 hectometers = 16.093 kilometers So for every step from the base unit to kilo, we moved the decimal 1 place to the left (the same direction as in the diagram below) Slide 16 Metric System If you move to the left in the diagram, move the decimal to the left If you move to the right in the diagram, move the decimal to the right kilo hectodeca meter liter gram deci centimilli Slide 17 Practice Problems 4 km = ______ m 7 m = ______ cm 20 cm = _______ mm 80 mm = ______ cm 910 cm = ______ m 73000 m = _______ km Slide 18 Practice Problems 4.000 km = 4000 m 7.00 m = 700 cm 20.0 cm = 200 mm 80 mm = 8.0 cm 910 cm = 9.10 m 73000 m = 7.3000 km Slide 19 Metric System Summary Base units in the metric system are meter, liter, gram Metric system is based on powers of 10 For conversions within the metric system, each step is 1 decimal place to the right or left Using the diagram below, converting to the right, moves the decimal to the right and vice versa