 # Scientific Measurements

## Presentation on theme: "Scientific Measurements"— Presentation transcript:

Scientific Measurements

Scientific Measurements
Measurement: a means of describing observations using numbers and a UNIT of measure (ex: 11 inches) - makes a comparison with a known standard - ALL measurements contain at least one of the four basic dimensional quantities (length, mass, time, temperature) Systems of measurement: Metric System (aka International System of Units (SI)

Basic Measurement Units
Unit Metric Instrument Time: instant something happens OR period of change Length: distance between 2 points Mass: amount of matter in an object Temperature: measurement of how hot or cold something is (average KE = average Kinetic Energy) Second (s), minute (min), hour (hr), year (yr) Meter (m), centimeter (cm), millimeter (mm), kilometer (km) Gram (g), kilogram (kg) Celsius (0C) Kelvin (0K) Clock, stopwatch, sundial, hour glass Meter stick, ruler, tape measure Balance, scale Thermometer

Derived Units Examples of Derived Units: Volume; Density
** Some properties are best described by using some mathematical combination of the basic quantities. These mathematical combination of basic quantities are referred to as DERIVED UNITS. Examples of Derived Units: Volume; Density Volume: amount of space an object takes up Regular Shape: Volume L . W . H cm . cm . cm = cm3 Irregular Shape: displacement method (1 ml = 1 cm3) Drop object in known volume of water and record the difference

Volume Practice: L x W x H
1. Find the volume of a block that is 5cm in length, 3cm in width, and 8 cm in height. 2. What would the volume be for the object below? 3. What would the volume be for the object below? 120cm3 60cm3 78in3

Let’s measure some irregular shapes!
What is the volume of the dinosaur in ml? 0.8 ml

Volume of irregular objects practice
3 ml 60 ml

Working With Numbers Every number has a decimal version (4 = 4.0)
Rounding off numbers: most of the time to the nearest 10th or 100th Every number has a decimal version (4 = 4.0) Rules: you always check the number to the right to decide > 5 Ex: < 4 Leave it alone thousandths tenths hundredths (5.363) (5.4) (5.36) The “rules” Five or more, raise the score Four or less, leave it rest

Rounding Practice Time
Working With Numbers Rounding Practice Time Round to the nearest tenths place: 3.73= 2. 65= 4.324= 18.957= = Round to the nearest Hundredths place: 6.546= 16.342= = 12.997= = 3.7 6.55 2.7 16.34 4.3 124.86 19.0 13.00 2345.6

Write the meaning and abbreviations for the following prefixes:
There are several metric unit prefixes. The ones we use in science are kilo-, hecto-, deka-, deci-, centi-, and milli. Write the meaning and abbreviations for the following prefixes: Kilo: Hecto: Deka: Deci: Centi: Milli: k, 1000 h, 100 da, 10 d, 0.1 c, 0.01 m, 0.001

To remember the order of the prefixes in order from largest to smallest use the following sentence:
King Henry Doesn't [Usually] Drink Chocolate Milk kilo-  hecto-  deka-  [unit]  deci-  centi-  milli- Each step is ten times or one-tenth as much as the step on either side: 1 kilometer = ____ hectometers = ______ dekameters = ________meters = _________ decimeters = ____________ centimeters = _______________ millimeters Alternatively 1 milliliter = ____ centiliters = _______ deciliters = _________ liters = ____________ dekaliters= ______________ hectoliters = ______________ kiloliters 10 100 1000 10,000 100,000 1,000,000 10 100 1000 10,000 100,000 1,000,000

The point here is that you move from one prefix to another by moving the decimal point one place, filling in, as necessary, with zeroes. To move to a smaller unit (a unit with a prefix some number of places further to the ____________ in the listing), you move the decimal place to the right that same number of places. Convert kilometers to centimeters. How many jumps is it from "kilo-" to "centi-“?________, to the right. Kilo- Hecto- Deka- [Meters] Deci- Centi- Milli So I move the decimal point five places to the right, filling in the extra space with zeroes: 12.54 12.54km= ______ cm Right 5 1,254,000

To move to a larger unit (a unit with a prefix some number of places further to the right in the listing), you move the decimal place to the __________ that same number of places. Convert 457 ml to hl How many jumps is it from “milli” to “hector”? ________, to the left. Kilo- Hecto- Deka- [Meters] Deci- Centi- Milli So I move the decimal point five places to the Left, filling in the extra space with zeroes: 457 ml= Left 5 . 0 0 hl

Practice Kilo- Hecto- Deka- [Meters] Deci- Centi- Milli
12mm =________dm 2) 4km=______cm 3) hm=______mm 0.12 400,000 567,800

Who wants more practice : Try, “Working With Numbers worksheet”
Volume Rounding Unit Conversions Try, “Working With Numbers worksheet”