+ Metrics - part of International System of Measurements (SI) Easy to use base 10 - each unit is 10x bigger than the next –better for converting Consistent – all scientists use the same units – better for collaborating

+ Countries That Do Not Use the Metric System Liberia Burma/Myanmar U.S. ‘we don’t need no stinking metrics’!...

+ The Magic of the Metric System: 10x! meter(m) gram(g) liter(L) k kilo- 1000x c centi - 1/100x 0.01x m milli- 1/1000x 0.001x Distance/length Mass Volume BASE UNIT h hecto 100x da deca 10x d deci 1/10x 0.1x smaller bigger MEASURED VARIABLE King Henry Died By Drinking Chocolate Milk

+ 1.0 kilo- milli- 1. You have 0.33 kilograms of laundry soap; how many grams? 2. Your water bottle is labeled 500mL; how many liters does it hold? g # of stair steps = # of decimal places L

+ How many millimeters in 1 centimeter? Measuring Length (m) How long is the line in cm? in mm? cm Measuring Mass (g) Please be careful with the scales! Keep clean Keep flat Use ‘tare’ or zero button to clear out the mass of the container 1cm = 10mm 2.8cm = 28mm

+ Geometric solids use cm 3 l x w x h Measuring Volume Irregular solids use water displacement Volume of object Liquids, use L mL of a rock!? 1mL =1cm3 = 1cc At eye level, read at the bottom of the meniscus What is the volume of the water? 15mL …NOT 15.1ml 10cm x 10cm x 10cm = 1,000cm3

+ What is the volume of water in the cylinder? What is the volume of the toy? Measuring Volume 43ml..each line is 1ml Note each line must be 0.2ml. 5.6 End volume -4.8ml Start volume 0.8ml toy’s volume

+ Wait! I measure distance in MILES!

+ Which is longer? A. 1 mile or 1 kilometer B. 1 yard or 1 meter C. 1 inch or 1 centimeter 1.6 kilometers 1 mile = 1 yard = meters 1 inch = 2.54 centimeters U.S. vs. Metric : Length

+ Which is larger? 1. 1 Pound or 100 Grams 2. 1 Kilogram or 1 Pound 3. 1 Ounce or 1000 Milligrams 100 kg = 220 pounds 1 ounce of gold = g U.S. v. Metric: Mass 1 pound = g

+ Which is larger? A. 1 liter or 1 gallon B. 1 liter or 1 quart C. 1 milliliter or 1 fluid ounce 1 gallon = 3.79L 1 fl oz = 29.53mL 1 12-oz can of soda ~ 355 mL 1 quart = liters U.S. v. Metric: Volume

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+ Dimensional analysis Converting One Unit to Another Determine these three facts: Your friend runs a 2.5mi route while you typically run a 5km one. Which of you ran the longer distance? What unit do you need to convert to? What conversions factor(s) can be used to ‘bridge’ the two? What value & units are you given to convert? 1mi =1.6km 2.5mi 1.6km x mi = 4km you rule!

+ Set up your conversion factor with the given units in the denominator & wanted units in numerator Multiply straight across; divide final fraction Start with the given units you have Cancel like terms (units) 2.5mi 1.6km x mi 2.5 (1.6km) = finish it! 1 (1) Conversion factor Go Hog Wild! You feel guilty ordering a 20 ounce steak – think about it in kg instead 20oz g x oz 1 kg x ---- = 1000g

+ Scientific Notation Digits plus the power of is a number Thus, 700 is the same as 7.0 x can be restated as 7.0 x can be restated as 10 x x 10 can be stated as 10 2 The moon is more than 384 thousand km from earth. Ex: Windsor to Disneyland is 745km, or 7.45 x 10 2 (700.0 is the same number)

+ Convert one value, using the ladder method, then compare 1) 200cg to g 6) 5 L to mL 11) 16 cm to mm 2) 104 km to m 7) 198 g to kg 12) 2500 m to km 3) 480 cm to m 8) 75 mL to L 13) 65 g to mg 4) 5.6 kg to g 9) 50 cm to m 14) 6.3 cm to mm Compare using, or =. 25) 63 cm 6 m 27) 5 g 508 mg 29) 1,500 mL 1.5 L 26) 536 cm 53.6 dm 28) 43 mg 5 g 30) 3.6 m 36 cm Practice