II. THE METRIC SYSTEM JWA6Vw JWA6Vw

Background When was the metric system created? The first practical realization of the metric system came in 1799, during the French Revolution, when the existing system of measure, which had fallen into disrepute, was temporarily replaced by a decimal system based on the kilogram and the metre.

Background (cont’d) Why is the metric system called a decimal system? The metric system is a called a decimal- based system because it is based on multiples of ten. Any measurement given in one metric unit (e.g., kilogram) can be converted to another metric unit (e.g., gram) simply by moving the decimal place.

Background (cont’d) If you’re a scientist, a student or a citizen of any country in the world except for the United States, Myanmar or Liberia, there’s no avoiding the metric system. The system, featuring meters, liters and kilograms, was adopted following the French Revolution and devised by a group of French scientists in an effort to create a system of standard measurements (at the time, thanks to local and regional practices, there were nearly 400 different ways to measure areas of land in France). If you’re a scientist, a student or a citizen of any country in the world except for the United States, Myanmar or Liberia, there’s no avoiding the metric system. The system, featuring meters, liters and kilograms, was adopted following the French Revolution and devised by a group of French scientists in an effort to create a system of standard measurements (at the time, thanks to local and regional practices, there were nearly 400 different ways to measure areas of land in France). Ideas for a rational, decimal-based system of measurement, expressed in multiples of 10, had been around since the 17th century, however. Abandoning old royal standards, the metric system’s developers sought to express everything in terms of logic and nature. One meter was one ten-millionth of the distance between the North Pole and the Equator; a milliliter was the volume of one cubic centimeter of water, whose weight would equal one gram. The first metric system also included the “stère,” equal to the volume of one cubic meter of stacked firewood. Ideas for a rational, decimal-based system of measurement, expressed in multiples of 10, had been around since the 17th century, however. Abandoning old royal standards, the metric system’s developers sought to express everything in terms of logic and nature. One meter was one ten-millionth of the distance between the North Pole and the Equator; a milliliter was the volume of one cubic centimeter of water, whose weight would equal one gram. The first metric system also included the “stère,” equal to the volume of one cubic meter of stacked firewood

A. WHY DO WE USE THE METRIC SYSTEM? 1. Almost all other countries are using the metric system. 2. Easy to convert between different units, based on the number Scientists need a universal way to communicate data (SI Units).

B. Metric Units Mass (amount of matter an object has) = grams (g) Mass vs. weight 2. Volume (the amount of space an object occupies) = liters (L) 3. Length (distance from one point to another) = meter (m) 4. Time (duration of an event) = seconds (sec)

Let’s look at mass, volume & length more closely! Let’s look at mass, volume & length more closely!

Measuring Liquid Volumes with a Graduated Cylinder 10 ml Graduated Cylinder Volume=_________ml 100 ml Graduated cylinder Volume=_________ml 25 ml Graduated cylinder Volume=__________ml

Measuring Mass 1) What is the mass of the object being weighed?_______________g79.3g June 2000

Measuring Mass 2) What is the mass of the object being weighed?____________g25.4

The longer lines on the metric ruler are called… centimeters centimeters

The shorter lines on the metric ruler are called… millimeters millimeters

Checkpoint One centimeter is divided into how many millimeters? 10 millimeters (mm) 10 millimeters (mm)

Figure 2: Calculating: Measure the turtle in figure 2 from the rear of its shell to the tip of its shell. Record its length in both centimeters and millimeters. 8.8 cm 8.8 cm 88 mm 88 mm

C. THE METRIC CONVERSION CHART (STAIRCASE METHOD) Kilo 1000 units Hecto 100 units Deca 10 units Basic Unit deci 0.1 units Centi 0.01 units Milli units To convert to a smaller unit, move decimal point to the right To convert to a larger unit, move decimal point to the left

TRY THIS USING THE STAIRCASE METHOD 1000 mg = ______ g Step 1: Determine if you are going to go up or down the ladder. Step 2: Determine how many steps there are from milligrams to grams. Step 3: Move the decimal point the amount of places that was determined in steps 1 & 2.

TRY THIS USING THE STAIRCASE METHOD 1000 mg = ______ g Step 1: Determine if you are going to go up or down the ladder. Step 2: Determine how many steps there are from milligrams to grams. Step 3: Move the decimal point the amount of places that was determined in steps 1 & 2. 1

TRY THIS USING THE STAIRCASE METHOD.15 L = __________ ml

TRY THIS USING THE STAIRCASE METHOD.15 L = __________ ml 150

TRY THIS USING THE STAIRCASE METHOD 16.7 cm = __________ hm

TRY THIS USING THE STAIRCASE METHOD 16.7 cm = hm

#1: Metric Measurement Lab Object Paperclip g mg kg Penny g mg kg Shoe g mg kg Finger nail cm mm m Height cm mm m Stride (one) cm mm m Pop can ml l kl Ice tray (one cube) ml l kl Dixie cup ml l kl mass volume length

Conclusion Questions: 1. Why is it important that all scientists use similar units? Give two reasons why is the metric system the best system for use in science. 2. Describe the process of measuring volume with a graduated cylinder (be specific). 3. I don’t understand how to use the “staircase method.” Explain (in detail) how the “staircase method” works, provide an example.