Today 9/28: 1. Take out your article, leave it on your desk 2. Discuss the article, paragraph by paragraph, with the person sitting next to you. Share your questions/connections/summary) 3. Lecture on metric conversions HW: Complete #1-11 on worksheet

9/28/12 Metric system COPY and respond to the following in your notes What units do scientists use to measure: a.) length? b.) mass? c.) volume? Copy the text in bold 3 times: Kilo-hecta-deka-unit-deci-centi-milli  You will need to memorize this! It will help you in all future science classes!

METRIC CONVERSION You can do Metric Conversion if: You can Count Up to Six and Know Your Left From Your Right

What are Metric Conversions? Sometimes we need to change from one measurement to another. This is usually done because the unit that is used is either too big or too small for that type of measurement.

Sometimes the number is too big for the unit being measured. 525,568 millimeters Sometimes the number is too big for the unit being measured.

Sometimes the number is too small for the unit being measured 0.00654 km Sometimes the number is too small for the unit being measured

How Do We Fix This Problem? We can correct these problems by doing a process called Metric Conversion. Metric Conversion: changing from one unit of measurement to another.

The Staircase Method We will be using a method called The Stair-step Method of Metric Conversion. It requires two things; one, that you be able to count to 6, and two, that you know your left from your right.

Staircase Method (copy this) Kilo- Hecto- Deka- base units Deci- Centi- Milli- Base units g, m, L Larger units Smaller units Move up the stairs, decimal moves to the  Move down the stairs, decimal moves to the 

How Do I Use This? Start: The first letter* of the prefix in the unit of measurement tells you which step to start on. Stop: The first letter* in the second unit of measurement tells you which step to stop on. *The exception to “first letter” being the prefix deka, which uses “da”. This shouldn’t pose a problem since there is no base unit that you will be using that starts with an “a”.

Using the stair step method Find your starting step Count the # of steps it takes to get to the step that you need to stop on. A. If you move to the  (downstairs) the decimal in the first measurement moves that many places to the . B. If you move to the  (upstairs) then the decimal moves to the . Fill any empty places with zeros.

The Stair-step Kilo- Hecto- Deka- base units Deci- Centi- Milli- Grams, liters,meters

525568 mm = ? m Millimeters are a very small amount of distance. You would not want to measure a large distance in a very small unit. Kilo- Hecto- Deka- base units Deci- Centi- Milli- Base units g, L,m Moved 3 to the  525.568m

0.00654 km = ? m Kilometers(km) are a fairly large unit of distance. You would not want to measure a small distance in a large unit, so we need to convert it to a smaller unit, the meter. Kilom is 3 steps to the right Therefore, 0.00654 km becomes 6.54 m.

Be able to count up to six and know your left from your right. Hey! This Is Easy! You bet it’s easy! Like we said on the first slide….. Be able to count up to six and know your left from your right. Now, get your stair-step sheet and your practice problems and do some more conversions!

What is the value for each prefix?

Exit Slip (When you are finished get out HW) Convert: 20kg to grams 10m to km 34cl to ml