DO NOW Identify the number of significant figures in each of the numbers below: 22.34 x 104 0.00000572 1,534,000 0.004506 4 3 4 4

Atlantic-Pacific Rule for SigFigs On what side is the Pacific Ocean? On what side is the Atlantic Ocean? If there is a period, start counting from the pacific (left) side, disregarding beginning zeros. If there is no period, start counting from the atlantic (right) side, disregarding the first zeros you encounter. left right

Friday, September 12, 2014 Unit: Metrics & Matter Key Question: Why are metric units easy to use?

1 “foot”…. literally How Big Is a Foot by Rolf Myller A King wanted to make a Queen a bed, but beds had not been invented yet. Nobody the King came in contact could figure out how big a bed was. Finally, the King said the bed had to be big enough to fit the Queen! He told the Queen to lie on the ground and walked around her, he said the bed needed to be 3 feet wide and 6 feet long. When the bed was made, it was too small because nobody knew how big a foot was. When they measured the King's foot, everyone knew how to make the bed.

Discussion If you cook how do you know how much food to add? Would you rather have 1 $10 bill, or a thousand pennies?

Homer Simpson Pre-Video question: Is Homer considered a good or bad employee? Why?

Why we measure with the Metric system Guess how many milligrams an elephant weighs. -4,500,000,000 mg What about kilograms? -4500 kg Which is easier to describe? The purpose of this slide is to explain to students why there are different prefixes in the metric system. Its easier to communicate values with these prefixes. Relate back to the money example. Why don’t we pay for everything pennies. A thousand pennies is the same amount of money as a $10 bill. However a $10 bill is much easier to carry. The physical quantity is like the money amount, and the prefix is the type of bill.

SI System of Units Le Systeme International d’Unites Also known as metric system Consists of a base unit and prefixes

Base Unit (meter, gram, liter, second) m, g, L, s 1 Prefix Abbreviation Conversion Factor (Base unit only) Mega M 1000000 Kilo k 1000 Hecto h 100 Deka da 10 Base Unit (meter, gram, liter, second) m, g, L, s 1 Deci d 1/10 Centi c 1/100 Milli m 1/1000 Micro µ 1/106 Nano n 1/109 Pico p 1/1012

Key Question Why are metric units easy to use, in terms of converting between units? Key Answer: All metric units are based on multiples of 10, which makes it easy to convert between units.

Mnemonic Devices Kilo Hecto Deka Base Deci Centi Milli Kings Have Diamonds But Diamonds Cost Money King Henry Died By Drinking Chocolate Milk

How many jumps does it take? Ladder Method 1 2 3 KILO 1000 Units HECTO 100 Units DEKA 10 Units DECI 0.1 Unit Meters Liters Grams CENTI 0.01 Unit MILLI 0.001 Unit How do you use the “ladder” method? 1st – Determine your starting point. 2nd – Count the “jumps” to your ending point. 3rd – Move the decimal the same number of jumps in the same direction. 4 km = _________ m Starting Point (kilo) Ending Point (base) How many jumps does it take? 4. 1 __. 2 __. 3 __. = 4000 m

Conversion Practice Try these conversions using the ladder method. 1000 mg = _______ g 1 L = _______ mL 160 cm = _______ mm 14 km = _______ m 109 g = _______ kg 250 m = _______ km 1 1000 1600 14000 0.109 0.250 Compare using <, >, or =. 56 cm 6 m 7 g 698 mg < >

Homework HW 1.3 - Online Quiz (Sig Figs) due TONIGHT @ 8pm HW 1.4 - Read p. 78-81 by Mon. 9/15 HW 1.5 - Online Quiz (Metric Conversions) due Mon. 9/15 8pm