Tuesday 1/26 Goal: Catalyst: Define the standard unit for length Design a rule for the number of digits recorded for different types tools * Turn in homework Catalyst: In science, should we just round to 2 decimal places? Why/why not? What does the last digit we record mean?

Create this chart in your notes In a group of 3, find the measurements for each of these columns. When you finish, white board your responses

Consensus Blank ruler (0 markings) measure 1 decimal place .1 ruler (10 markings) measure 2 decimal places .01 ruler (100 marking) measure 3 decimal places The last decimal place is an educated guess!

Questions What information is important when communicating these measurements with students in another classroom? When using the unmarked ruler, how did you deal with measures that did not come out to a whole number? What basis did you use to determine this? Are you certain that your answer is correct? Why/why not?

More Questions Is it possible to communicate your measures with other students in other groups? What would you have to include for them to understand your measurement? Would it be possible to communicate your measurements with someone who does not speak English? Explain.

Which of the rulers used would have been better for measuring the length of the room? Why? Which of the rulers would have been better for measuring the length of a paper clip? Why? Which, if any, of the rulers used would be good for measuring the distance between cities? Explain

Which of these rulers would you use to measure your height to the nearest 0.01 m? Why did you choose this ruler?

KHD_dcm

Calculations: 5.0 meters x 100 cm = mark meter 3250 cm x meter = Room 100 cm

More Calculations How many centimeters are there in 27.3 millimeters? How many meters are there in 1234 centimeters? A car traveled 456 km, how far did it go in meters? There are 1,000 micrometers in 1.0mm; how many micrometers are there in 3.75 cm?

Did you meet today’s goal What would the proper measurement be for the following? If a paper is 356 cm, long, how many meters is it? 3.0 3.2 3.4 3.6 3.8

Homework Everyone Convert the following: 34.5 Km  ? dm 780.2 cm  ?Hm 91.45 mm ?m 0.0192 Dm ? cm 15.32 dm  ? Dm 1st & 2rd Block Where in Chemistry do you think you will need to know different units of the meter? 3rd Block Where in earth science do you think you will need to know different units of the meter?