Metric System Notes In this presentation we will review the metric system. Please fill out your note sheet in your science journal as you go through the presentation.

METRIC SYSTEM -also called the International System of Units or SI. -used all over the world -measurements are organized in factors of 10. -came to be because of the need for common standards and specifications for products, machinery, and tools all over the world for trading and selling. In Science, we use the metric system also called the International System of Units or SI rather than the customary system which you may be used to. In class, we will commonly refer to metric units as the SI unit. This system is used all over the world and was developed so that there was a common measurement system among all countries to better communicate on products, machinery, and tools for trading and selling.

LENGTH/DISTANCE Length is measured using a ruler or meter stick. The SI Unit of length is m (meters). To measure the length of an object or a distance, we use a meter stick. Many times your ruler or meter stick will have both customary and metric units. You want to be sure to use the side of your tool that has the correct SI unit which is meters. Inches, feet, or yards will never be used in our class.

VOLUME Volume measures how much space an object takes up. Volume is measured in three different ways. Volume is a measurement of how much space an object takes up. Solids, liquids, and gases take up space and would therefore all have a volume. We measure volume of different substances in 3 different ways.

VOLUME OF A LIQUID Volume of liquids are measured using various lab tools: graduated cylinder, beaker, flask etc. The SI Unit is l (liters) To measure the volume of a liquid, we would use tools in our labs such as a beaker, graduated cylinder, or flask. The SI unit for volume of a liquid is liter.

VOLUME OF A REGULAR SOLID Use a ruler to measure the length, width, and height then multiply. Volume= L x W x H The SI Unit is cm3. (centimeters cubed) To measure the volume of a regularly shaped solid object such as a cube or other rigid object, we use a metric ruler to find the length, width, and height in centimeters. We then multiply those 3 measurements following the formula length times width times height. After multiplying, our answer would be labeled with the SI unit centimeters cubed.

VOLUME OF AN IRREGULAR SOLID Use the displacement method. Fill a graduated cylinder to any predetermined volume and carefully add the object. Find the new volume of the liquid and then subtract. The SI Unit is cm3. (centimeters cubed) To measure the volume of an irregular solid, we use the water displacement method. To find this measurement, you would fill a graduated cylinder with water to a predetermined volume (in this example, 200 mL). Then place the irregular solid into the graduated cylinder and see how much the water rises. In this example, the water rose to 260 milliliters. You now subtract the original volume from our new volume to receive the actual volume of the irregular solid in the water which would be 60 centimeters cubed. This represents how much space the solid takes up by causing the water to rise. I used the SI unit centimeters cubed for the volume because the object is a solid; only liquids can be measured in mL.

MASS (not the same as weight!) A measurement of how much matter (or stuff) an object has The SI unit for mass is grams (g) The lab tool used to measure mass is the triple beam balance Mass is the measure of how much “stuff” or matter an object is made of. This is different than the weight of an object. We use a triple beam balance to find this measurement. The SI unit for mass is grams.

TEMPERATURE Temperature is measured using a thermometer. The SI Unit for temperature is C (degrees celcius) Fun Fact: Water Freezes at 0c (32f) Water Boils at 100c (212f) Body Temperature is 37c (98.6f) To measure the temperature of a substance, we use a thermometer. The SI unit for temperature is Celcius.

Metric Base Units Since objects come in all shapes and sizes, scientists use units to express how big or how small, how long or how short, how heavy or how light an object is. Kilo is the largest while Milli is the smallest. All metric units have a base unit. For example, the base unit for length is meter. The base unit for mass is gram. We can add different prefixes to the base unit depening on the object or substance we are measuring. For instance, we would use millimeter to measure the length of a ladybug because it is small while we might use a kilometer to measure the length of a football field because it is large. Let’s Practice this!

1. I want to measure the volume of a public swimming pool 1. I want to measure the volume of a public swimming pool. What SI unit would I most likely use for this measurement? 2. I want to find the lenth of a pencil. What SI unit would I most likely use for this measurement? Read Q. Pause. You should be thinking kiloliter. A public pool is quite large and can hold a lot of water! Read Q2. Pause. You should be thinking centimeters. A pencil is much smaller than a meter which is just over 3 feet. Great job!

The End! You have made it to the end of the presentation. If you missed any spots in your journal notes you can go back in this presentation and hear them again.