Presentation on theme: "Measurements. Units Unit- what we measure something in Example – 32 feet – 85 seconds – 0.004 lbs – 98.6˚F – 0.6 m Units."— Presentation transcript:
Units Unit- what we measure something in Example – 32 feet – 85 seconds – lbs – 98.6˚F – 0.6 m Units
Check yourself Which of the following are units? feet temperature meters length miles time hours kilograms dollars
SI Units What scientists (and almost everybody else) uses Our Units (what we use)SI Units (what everyone else uses) LengthFeet (ft)Meters (m) TimeSeconds (s) Weight (how much gravity pulls us down) Pounds (lbs)Newtons (N) Mass (how much stuff there is in an object) Kilograms (kg)
Measuring length Meter stick Larger than a meter stick – 1000 meter sticks= 1 km Smaller than a meter stick – 1 meter= 100 cm – Even smaller 1 meter= 1000 mm
Joe owns his own company He needs 1200 gold pieces just this length for his new invention
He does a quick measurement and writes down the length as 3.5 cm. His: 3.5 cm Real: 3.42 cm Difference of 0.08 cm
Oops! His quick measurement: 3.5 cm Real: 3.42 cm Difference of 0.08 cm If he orders 1200 pieces, each 3.5 cm…. 96 extra cm 5 dollars an inch? = $ Measuring properly is important!
Measuring You can guess one number
Measuring You can guess one number. 7.6 cm
Try measuring here
Try measuring here: 2.37 cm
Measuring Length correctly You get to guess one number.
How about this one?
MASS How much stuff an object has NOT how much an object weighs Mass is measured in kilograms (kg).
Triple Beam Balance
Memorize this In order to make metric conversions we need to know our conversion factors. We will need to memorize our conversion factors for metrics. We can do this with the following pneumonic device: King Henry Died Monday drinking chocolate milk
What does that mean? King Henry Died Monday drinking chocolate milk Kilo Hecto Deca Meter deci centi mili NOTICE THAT THE WORDS AFTER METER ARE NOT CAPITALIZED!!!!
Sample Problem 23 cm = ____?____ Dm We will use stair steps to make our conversions
K H D M d c m
Sample Problem 23 cm = ____?____ Dm
K H D M d c m 1.Put a decimal in front of the number if there isnt one already. 23. cm 2. Find the starting point. 3. Count the number of steps to get to the ending point. chocolate 1 2 3
Sample Problem Move the decimal that many places over Answer 23 cm = Dm
Another sample 7.8 Km = ____?______dm
7.8 Km = dm
Now you try 1.14 mm = ___________M Hm =___________cm 3.92 M =_____________Km Dm =__________dm Km = __________mm