Measurements What are US customary (English) units and why created?  Beginning with Egyptians, the bible, Babylonians.  Measured using hands, forearms, stride lengths.  Time was measured using sun(1 year & 1 day) and moon (1 month).  Problem - Everyone had different units.  For example - King Henry I said that a foot would be the length of his foot and the yard the length from the tip of his nose to his fingertips.

Problem? - –Kings changed –Different countries = different rulers –Everyone had to know what the length was, not international accepted US Customary units ex) yard, feet, pound, ounce, gallon, teaspoon, mile, quart, pint, Fahrenheit, calorie

Why called US Customary units?  When our constitution was created Thomas Jefferson pushed for the metric system, but America did not adopt it.  Now we are the only industrialized nation in the world to use the English system. Not even the English use it.  In fact only US, Liberia, and Burma have not fully adopted the metric system.  This is why it is now called the US customary units

In US Customary units: 12 in = 1 ft 3 ft = 1yd 1760 yd = 1 mile. 16oz = 1pound This is a lot to remember and hard to calculate. Ex) what is 12*1760=

Metric Units – WHY?: A need for a standard unit to use internationally was realized by the scientific community during the French Revolution. Determined things with a base of 10 easier to manipulate and work with. The unit of length was to be a 1/10 millionth of the distance from the North to the South Pole along the meridian. (which does not change).

In Metric: Conversion is easy. Consistent through all units. 1000g = 1kgand100cm =1m 1000m = 1km1000m=1km 1000s = 1ks1000mm=1m What is: a)590/1000= b)590*1000 = c)590/10

SI UNITS To further simplify metric units SI (Standard International) units were created. There are 7 SI units. All metric measurement is based on the 7 SI units Type of measurementSI unitstandard usedother types of units using SI distancemeter (m)length light travels in 1/ secondsvelocity = m/s, volume = m 3, area = m 2 timesecond (s)cycles of the radiation produced by cesium 133frequency = Hertz (1/s) masskilogram (kg)cylinder of platinum-iribidium alloy held in Paris & US force = Newton (kg m/s 2 ), Power = Watt (kg m 2 /s 3 ) temperatureKelvin (K)based on absolute zero, coldest temperature possible Celsius is also used Kelvin = Celsius electric currentAmpere (A)related to force between 2 current carrying wires 1 volt = 1 Watt/ Amp 1 Ohm = 1 Volt/Amp Luminous intensitycandela amount of substancemole (mol)# of atoms in kg of carbon 12

Prefixes used with SI units Examples of base SI units that use prefixes – meter, liters, seconds, grams, newtons, joules, watts, bytes to name a few. Example = micrometer, milliliter, nanosecond, kilogram, megawatt. The following conversions must be memorized: nano, micro, milli, centi, kilo, mega

This chart reads: 1 picometer (pm) = m 1nm = m 1  s = s 1mL = 1/1000 L 1cm = 1/100 m 1kJ = 1000J 1MW = 1,000,000 W PrefixSymbolFraction of Base unit –like those mentioned above picop1/1,000,000,000,000 or nanon1/1,000,000,000 or micro  1/1,000,000 or millim1/1,000 or centic1/100 or base unit hectoh100 or 10 2 kilok1000 or 10 3 megaM1,000,000 or 10 6 gigaG1,000,000,000 or 10 9 teraT1,000,000,000,000 or 10 12

1)What units would I use to measure the length of an ant? a) Customary units? b) Metric units? a) Inchb) millimeter (mm) 2) What units would I use to measure the length of an pencil? a) Customary units? b) Metric units? 3) What units would I use to measure the length of a football field? a) Customary units? b) Metric units? 4) What units would I use to measure distance to New York? a) Customary units? b) Metric units? 5) What units would I use to measure your mass/weight? a) Customary units? b) Metric units? 6) What units would I use to measure amount of liquid in bottle of milk? a) Customary units? b) Metric units?

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

Try these conversions using the ladder method mg = _______ g 1 L = _______ mL160 cm = _______ mm 14 km = _______ m109 g = _______ kg 250 m = _______ km Conversion Practice Compare using, or =. 56 cm 6 m 7 g 698 mg 11,0001,600 14, <>

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 Metric Conversion Challenge kg cmmmm kmmL gLmg 25, , ,000 5,

Compare using, or =. 25) 63 cm 6 m 27) 5 g 508 mg 29) 1,500 mL 1.5 L 26) 43 mL 5 L 28) 3.6 m 36 cm < > <> =

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