chapter 5 Measurements & Calculations Warning! Lots of math (not tough math, but lots of it)

Remember there are qualitative and quantitative observations This chapter deals with the quantitative! called measurements

these measurements are not just numbers they have units as in 5 millimeters, 75 people, 16 mph, etc. but first…

5.1 scientific notation Some numbers are just too darn big or too small to deal with reasonably Scientific Notation is a method for making very large or very small numbers more compact and easier to write. as in: 64,400,000,000 can be written 6.44 x 1010 it’s easy! :)

N = integer (+/- whole #) Description: scientific notation must be written as the product of a number between 1 and 10 and the appropriate power of 10 M x 10n 1 < M ≤ 10 N = integer (+/- whole #) just count how many times you have to move the decimal point to get a number between 1 and 10 if the number is getting smaller the exponent will get bigger and vice versa

examples 238,000 2.38 x 105 1,500,000 1.5 x 106 0.00043 4.3 x 10-4 0.135 1.35 x 10-1 357 3.57 x 102

5.2 units Units are used everyday to give meaning to numbers go into a restaurant, sit down, just tell the waitress “two,” and see what you get Units are used everyday to give meaning to numbers people have used them since, like, forever…

the English system is used in the US; the metric system is used everywhere else scientists everywhere use metric and standardized it into the International System (SI)

these are the basic units of SI know them, love them, marry them

m and these are the prefixes we use to make them even more convenient “1 mm” is easier to use & write than “one thousandth of a meter” know them, love them, marry them

5.3 measurements of length, volume, and mass length is based on the meter

volume is how much 3D space something takes up SI unit is the m3 one thousandth of that is the dm3, aka the liter 0.001 of that is cm3 = mL

graduated cylinder we mostly measure volume with a but also these critters, all of which are marked on the side

Remember that when you use the Graduated cylinder to read the bottom of the meniscus

mass is measured in grams (even though SI unit is kg) measured with a balance

this is a table to get you better acquainted with it all