Measurement & Scientific Tools NOS L2 How to convert within the metric system Ms. Ladron De Guevara © Copyright 2003 - 2004.  M. J. Krech. All rights reserved.

The Metric System The metric system is a measurement system based on our decimal (base 10) number system. Other countries and all scientists and engineers use the metric system for measurement.

Do you remember… King Henry?

The pneumonic: Memorize this! King Henry Died Unexpectedly Drinking Chocolate Milk Memorize      this!

SI Base Units Quantity Measured Unit (Symbol) Length Meter (m) Mass Kilogram (kg) Time Second (s) Electric Current Ampere (A) Temperature Kelvin (K) Substance Amount Mole (mol) Light Intensity Candela (cd)

Metric Prefixes Prefix Symbol Factor Number Factor Word Kilo- k 1000 Metric Units The metric system has prefix modifiers that are multiples of 10. Prefix Symbol Factor Number Factor Word Kilo- k 1000 Thousand Hecto- h 100 Hundred Deca- da or D 10 Ten Unit m, l, or g 1 One Deci- d .1 Tenth Centi- c .01 Hundredth Milli- m .001 thousandth

You must also know… …how to convert within the Metric System. Here’s a good device: On your paper draw a line and add 7 tick marks:

Next: Above the tick marks write the abbreviations for the King Henry pneumonic: k h d u d c m m l g Write the units in the middle under the “U”.

Let’s add the meter line: k h d u d c m km hm dam m dm cm mm L g

Let’s add the liter line: k h d u d c m km hm dam m dm cm mm kL hL daL L dL cL mL g Deca can also be dk or da

Let’s add the gram line: k h d u d c m km hm dam m dm cm mm kl hl dal l dl cl ml kg hg dag g dg cg mg

How to use this device: Look at the number given. Check if it has a decimal. If it does use that decimal & proceed to step 2. If it does not place a decimal at the end of the number. Ex: 400. Look at the unit that the number has. Locate it on the number line and circle the unit. 3. Locate the unit that you want to covert to and circle it. Move to new unit, counting jumps and noticing the direction of the jump. Move decimal in original number the same # of spaces and in the same direction.

Example #1: Look at the problem. 56 cm = _____ mm Look at the unit that has a number. 56 cm On the device put your pencil on that unit. k h d u d c m km hm dam m dm cm mm

Example #1: Move to new unit, counting jumps and noticing the direction of the jump! k h d u d c m km hm dam m dm cm mm One jump to the right!

Example #1: Move decimal in original number the same # of spaces and in the same direction. 56 cm = _____ mm 56.0. One jump to the right! Move decimal one jump to the right. Add a zero as a placeholder.

Example #1: 56 cm = _____ mm 56cm = 560 mm

Example #2: Look at the problem. 7.25 L = ____ kL Look at the unit that has a number. 7.25 L On the device put your pencil on that unit. k h d u d c m kl hl dal L dl cl ml

Example #2: Move to new unit, counting jumps and noticing the direction of the jump! k h d u d c m kl hl dal L dl cl ml Three jumps to the left!

.007.25 Example #2: Move decimal to the left three jumps. (3) Move decimal in original number the same # of spaces and in the same direction. 7.25 L = ____ kL .007.25 Three jumps to the left! Move decimal to the left three jumps. Add two zeros as placeholders.

Example #2: 7.25 L = ____ kL 7.25 L = .00725 kL

Example #3: Try this problem on your own: 45,000 g = ____mg k h d u d c m kg hg dag g dg cg mg

45,000.000. Example #3: Three jumps to the right! k h d u d c m kg hg dag g dg cg mg Three jumps to the right! 45,000.000.

Example #3: 45,000 g = 45,000,000 mg Three jumps to the right!

Example #4: Try this problem on your own: 5 cm = ____ km k h d u d c m km hm dam m dm cm mm

.00005. Example #4: Five jumps to the left! k h d u d c m km hm dam m dm cm mm Five jumps to the left! .00005.

Example #4: 5 cm = .00005 km Five jumps to the left!

Examples #5-9: Solve these five problems on your own. Show your answers to your teacher. You may choose to use the King Henry Notes. You may choose the King Henry Staircase. You may also choose to make a King Henry Slider.

Examples #5-9: (5) 35 mm = ____ cm (6) 14,443 L = ____ kL (7) 0.00056 kg = ____ g (8)35.4 L = ____ mL (9)16 mm = ____ km

Conversion Practice Try these conversions using the ladder method. 1) 1000 mg = _______ g 3) 1 L = _______ mL 5) 160 cm = _______ mm 2) 14 km = _______ m 4) 109 g = _______ kg 6) 250 m = _______ km Compare using <, >, or =. 7) 56 cm 6 m 8) 7 g 698 mg

Metric Conversion Challenge Write the correct abbreviation for each metric unit. 1) Kilogram _____ 4) Milliliter _____ 7) Kilometer _____ 2) Meter _____ 5) Millimeter _____ 8) Centimeter _____ 3) Gram _____ 6) Liter _____ 9) Milligram _____ Try these conversions, using the ladder method. 10) 2000 mg = _______ g 15) 5 L = _______ mL 20) 16 cm = _______ mm 11) 104 km = _______ m 16) 198 g = _______ kg 21) 2500 m = _______ km 12) 480 cm = _____ m 17) 75 mL = _____ L 22) 65 g = _____ mg 13) 5.6 kg = _____ g 18) 50 cm = _____ m 23) 6.3 cm = _____ mm 14) 8 mm = _____ cm 19) 5.6 m = _____ cm 24) 120 mg = _____ g

Compare using <, >, or =. 1) 63 cm 6 m 2) 5 g 508 mg 3) 1,500 mL 1.5 L 4) 536 cm 53.6 dm 5) 43 mg 5 g 6) 3.6 m 36 cm

Accurate Precision Validity

The Science of Measurement: Accuracy vs. Precision Accurate means "capable of providing a correct reading or measurement." In physical science it means 'correct'. A measurement is accurate if it correctly reflects the size of the thing being measured. Precise means "exact, as in performance, execution, or amount. "In physical science it means "repeatable, reliable, getting the same measurement each time." We can never make a perfect measurement. The best we can do is to come as close as possible within the limitations of the measuring instruments. Validity refers to measuring what we really need to measure. The truth in the process used to measure.

Suppose you are aiming at a bull's eye with each of five darts. Low Accuracy High Precision High Accuracy Low Precision High Accuracy High Precision This is a precise but not accurate. The darts are together but did not hit the bulls eye. This is an accurate but not precise. The darts are not clustered, but their 'average' position is the center of the bull's eye. This pattern is precise and accurate. The darts are clustered and their average position is the center of the bull's eye.

Scientific Tools Science Journal: One of the most important tools in science is where a scientist keeps their plans, procedures and findings.

Scientific Tools Graduated Cylinders - a piece of lab equipment used to measure the volume of a liquid and irregularly shaped objects. Units used are Liters (L)

Scientific Tools Beakers - simple container for stirring, mixing and heating liquids commonly used in many laboratories. Unit used is Liters (L), (mL)

Scientific Tools Flasks - can be used for making solutions or for holding, containing, collecting, or sometimes volumetrically measuring chemicals, samples, solutions, etc.

Scientific Tools Petri Dish - a shallow glass or plastic cylindrical lidded dish that biologists use to culture cells or small moss plants.

Scientific Tools Triple Beam Balance - typical mechanical balance. Units measured are Grams (g)

Scientific Tools Thermometer: measures temperature of substances. Compound Microscopes: allow people to observe objects that are normally too small to see with just your eyes. Computer: process, gather and decipher information.

The End