Instructional Objective: 1.Identify Standards of Measurements 2.Learn about SI units

Standards of Measurements Standard: Is an exact quantity that people agree to use for comparison

International System of Units (SI Units) *came from the French words “Le Systeme Internationale d’Unites”. Are universally accepted and understood by Scientists Each type of SI measurements has a base unit

© 1999 Heather Holliday

SI comes from the French La Systeme Internationale. SI and metrics use the same units and processes. There are certain steps to follow when converting between units of metric measure: 1--Use the following short cut chart k h da * d c m 2--Find your original place on the chart by looking at the problem to identify the number with the unit (mark that place) 3--Find your target place on the chart by looking at the problem to identify the number without the unit (mark that place differently) 4--Count how many places you would need to move between the original and target places 5--Always move your decimal in the direction you moved on the chart from the original to the target 6--Rewrite the number given in the problem and apply steps 4 and 5 to the number 7--Write the answer in the blank provided

SI Base Units

Common SI Prefixes

Now let’s see how well you can perform some conversions!! Example problems 10 km = _____ dm 0.1 hm = _____ m 1cm = _____ hm 0.01 m = _____ mm 100 dg = _____ dag 10 hg = _____ kg 0.1 mg = _____ dg cg = _____ mg 1 kg = _____ g 0.01 dag = _____ cg

The centigrade (Celsius) scale temperature (K) = temperature (°C) the melting point of water is = 0°C = K the boiling point of water is = 100°C = K

reading a graduated cylinder

The boiling point *is the temperature at which the vapor pressure of a liquid is one atmosphere. *Units - K (Kelvin)

The Fahrenheit scale the melting point of water = 32°F the boiling point = 212°F.

The SI unit of temperature is Kelvin (K). Notice that there is no degree sign used with the abbreviation. To covert from Celsius to Kelvin temperatures: C--> K+ 273 K--> C- 273 CelsiusKelvinFahrenheit Freezing: Boiling:

Dervied units: are combinations of SI units. Volume: amount of space occupied by an object. Volume=Length X Width X Height V= l X w X h This is used to calculate the volume of a cube and combines three length measurements together. Density: the mass per unit volume of a material. Density=Mass/Volume D=m/V This is a combination of units of mass and volume.

Density of the regular object Mass- find the mass of the object using a balance Volume- To find the volume by measuring the length, width, and height. Then calculate density=mass/volume

Density of the irregular object Mass- find the mass of the unknown using a balance Volume- To find the volume, first measure the water that can immerse the irregular object in a graduated Cylinder. Then dropped the object in the cylinder and note the displacement measurement. Density = mass/volume.