Catalyst What piece of lab equipment would you use to measure…  The volume of water?  The volume of a square block?  The mass of a diamond?  The temperature of a solution being heated?  The length of the classroom?  The density of a weird shaped rock? (CHALLENGE!)

Today’s Agenda  Catalyst  Short Diagnostic  Standard International Units  Prefixes – it just makes too much sense  Accuracy and Precision  How accurate/precise are you?  Exit Question

Today’s Objectives  SWBAT identify and use SI units and SI prefixes.  SWBAT distinguish between accuracy and precision.

Short Diagnostic  You have 4 minutes to show me what you know!  We will go over the answers while taking notes!

Measurement Notes Key Point #1: Scientists have a standard international way of measuring volume, mass, and length known as SI Why do you think scientists do this?

Standard International Units  Volume is the amount of space an object takes up; measured in liters (L) or centimeters cubed (cm 3 )  Mass is the amount of matter in an object; measured in grams (g)  Length is the distance from one point to another; measured in meters (m)

What unit should you use to answer the following questions??? 1. How far is it from the Earth to the Sun? 2. How much water can I fit into the beaker? 3. How much matter can we put on the table before it breaks? METERS LITERS GRAMS

Prefixes Key Point #2: You can use prefixes to adjust the value of each of these units. Why would scientists do this?

 Well… fine… what are these prefixes?

yotta- (Y-) septillion zetta- (Z-) sextillion exa- (E-) quintillion peta- (P-) quadrillion tera- (T-) trillion giga- (G-) billion mega- (M-) million kilo- (k-) thousand hecto- (h-) hundred deka- (da-)101 ten deci- (d-) tenth centi- (c-) hundredth milli- (m-) thousandth micro- (µ-) millionth nano- (n-) billionth pico- (p-) trillionth femto- (f-) quadrillionth atto- (a-) quintillionth zepto- (z-) sextillionth yocto- (y-) septillionth

Well… ok, we generally only use a few of the prefixes…PrefixMultiplier Power of ten giga, G1,000,000,000 (billion) grams in a Gg10 9 mega, M1,000,000 (million)10 6 kilo, k1,000 (thousand)10 3 hecto, h100 (hundred)10 2 deka, da10 (ten)10 1 BASE110 0 deci, d1/10 (tenth)10 -1 centi, c1/100 (hundredth) of a gram in a cg10 -2 milli, m1/1,000 (thousandth)10 -3 micro, µ1/1,000,000 (millionth)10 -6 nano, n1/1,000,000,000 (billionth)10 -9

Figure it out! Fill in the blanks! 1. 1,000 milligrams = 1 gram meters = 1 dekameter 3. 1,000,000,000 liters = 1 gigaliter 4. _____________ centimeters = 1 meter 5. 1,000,000 micrograms = _________ gram meters = ____________ hectometers

Figure it out! Fill in the blanks! 1. 1,000 milligrams = 1 gram meters = 1 dekameter 3. 1,000,000,000 liters = 1 gigaliter 4. _____________ centimeters = 1 meter 5. 1,000,000 micrograms = _________ gram meters = ____________ hectometers

Having trouble? 10 # If the number is negative, If the number is positive, move the decimal to the left move the decimal to the right

Prefixes can be used for all units  Let’s use a milli- for an example  You can have a…  Milli gram – one-thousandth of a gram  Milli meter – one-thousandth of a meter  Milli liter – one-thousandth of a liter  If Lil’ Wayne was really that rich, he’d be singing a mega, a mega, a mega…

Knowing what you know now…  Correct your pre-test! 1. A 2. D 3. D 4. B 5. D 6. A

Who’s a balla?!?!?!? Who’s a shot calla?!?!? I hope you all are! If you’re not, come to tutoring!!!!

Precision/Accuracy Activity (15 min)  You will need a package of markers, a bulls eye, and a ruler.  Follow the written procedure.  Don’t worry about answering questions at the end….yet!

 Now that we got measurement down, let’s talk about accuracy

Accuracy  Key Point #3: Accuracy is how close you are to the correct or accepted value of a measurement.  Example of GOOD ACCURACY: Throwing a dart close to the bulls eye  Example of GOOD ACCURACY: If something is known to have a mass of 500 g and you measure 499 g

Precision  Key Point #4: Precision is how close a series of measurements are to one another.  REPEATABILITY!  Example of GOOD PRECISION: Throwing a dart and hitting the same spot 3 times in a row  Example of GOOD PRECISION: If something is known to have a mass of 500 g and four students measure it to be 497 g

Good Accuracy Good Precision Good Accuracy Poor Precision Poor Accuracy Good Precision Poor Accuracy Poor Precision

Group Activity  Please answer questions at the end on the back of your group paper  Please leave group assignment in folder!

Exit Question Describe the accuracy (A) and precision (P) of 1 & 2. What prefix/unit would you use to measure the volume of cold drink in a can? What prefix/unit would you use to measure the length of your pinky?