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Math Unit. Fill in the blanks in your notes with the words bolded in purple . Warm-up Question . The United States is one of how many countries in the world that still use the imperial system of measurement? What are the other countries?. 3. Liberia Myanmar (formerly Burma).
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Math Unit Fill in the blanks in your notes with the words bolded in purple.
Warm-up Question The United States is one of how many countries in the world that still use the imperial system of measurement? What are the other countries? 3 • Liberia • Myanmar • (formerly Burma)
Units of Measurement • SI Units • a system of units of measurements devised around seven base units and the convenience of the number ten.
Units of Measurement • Metric System
Move the decimal to the left Move the decimal to the right Sample problem Convert the following 53 hg = ________dg Start with 53. Move the decimal 3 spaces to the right 53 Fill in the empty spaces with zeros 53000 dg
Move the decimal to the left Move the decimal to the right Sample Problem Convert the following 300 cg = ________kg Start with 300. Move the decimal 5 spaces to the left 300 Fill in the empty spaces with zeros 0.00300 kg
Move the decimal to the left Move the decimal to the right Units of Measurement • Examples… • 1000 mg = __________ g • 160 cm = __________ mm • 109 g = __________ kg • 1 L = __________ mL • 14 km = __________ m 1 1600 0.109 1000 14000
Exit Question • Now that you are a metric master, would it be easier to convert inches to miles or centimeters to kilometer? Explain.
Warm-up Question • What is the significance of this number? 602000000000000000000000 It’s a mole!!! (the SI unit for a amount of a substance)
Scientific Notation • Scientific notation expresses numbers as a multiple of two factors: a number between1 and 10 (coefficient); and ten raised to apower, or exponent. • The exponent tells you how many times the first factor must be multiplied by 10. • When numbers larger than 1 are expressed in scientific notation, the power of 10 is positive. • When numbers smaller than 1 are expressed in scientific notation, the power of 10 is negative. Exponent Coefficient
Scientific Notation • Examples… • Change the following data into scientific notation: • The diameter of the Sun is 1,392,000 km. • The density of the Sun’s lower atmosphere is 0.000000028 g/cm3. km g/cm3
Scientific Notation • Adding and Subtracting Using Scientific Notation • The exponents must be the same before doing the arithmetic. Convert the smaller number to the bigger one, by moving the decimal to the right. • Add or subtract the coefficient. • Keep the exponent the same. • Make sure your answer is written in proper scientific notation. • Example… • 1.26x104 kg + 2.5x103 kg = ____________________ kg 1.51x 104
Scientific Notation • Multiplying and Dividing Using Scientific Notation • Multiply or divide the coefficients. • Add the exponents (for multiplication) or subtract the exponents (for division). • Examples… • (2x103 cm) x (3x102 cm) = ____________________ cm2 • (9x108 g) ÷ (3x10-4mL) = ____________________ g/mL 6 x 105 3 x 1012
Exit Question • Scientific notation should come in handy when expressing what kinds of quantities in chemistry? Submicroscopic things like the size of an atom or the number of atoms in a substance.
Warm-up Question • How can you simplify this problem before you calculate the answer? =
Dimensional Analysis (Factor Label) • A conversion factor is a ratio of equivalent values used to express the same quantity in different units. • A conversion factor is always equal to 1. • Dimensional analysis is a method of problem-solving that focuses on the units used to describe matter. • Dimensional analysis often uses conversion factors. • When you convert from a large unit to a small unit, the number of units must increase. • When you convert from a small unit to a large unit, the number of units must decrease.
Factor Label Method of Conversion Use conversion factors to systematically move from one unit to the next, cancelling out units on the diagonal in each step. Convert 18 m = _______ cm 1 m = 100 cm 100 cm = 1 m 100 cm 18m = 1800 cm 1 m
Dimensional Analysis • Examples… • How many seconds are there in 24 hours? • A car is traveling 90.0 kilometers per hour. What is its speed in miles per minute? 60min 60sec 24 hr = 86400 sec 1 hr 1 min 90 km 0.62mi 1 hr = 0.93 mi/min 1 hr 1 km 60 min
Exit Question On the planet Rigel, Rigellians have developed a system of measurements called S.U., or Systems Universal. Here is the conversion table for the measurements of distance: 1 gleem = 27 blops 1 blop = 34 riddigs 1 riddig = 42 chirks 1 chirk = 9 fuggles 10 fuggles = 52 hippers 2.5 hippers = 1.2 zookas 1 zooka = 7 wenzels Use the Factor Label Method and the conversions above to solve the problem. How many fuggles are there in 19 blops?