## How to: Conversions using the factor-label method (Wikipedia)

August 26, 2010 by

2

Brief instructions and example showing how to convert between units (say, from mi to m) using conversion ratios. Converting from one dimensional unit to another is often somewhat complex and being able to perform such conversions is an important skill to acquire. The factor-label method, also known as the unit-factor method or dimensional analysis, is a widely used approach for performing such conversions

## How to: Entering scientific notation on a calculator (TI)

August 26, 2010 by

0

Short 'how to' showing how to enter scientific notation on a TI (Texas Instruments) calculator. Use the Enter Exponent or [EE] key to enter numbers in scientific notation. The [EE] key is used to denote x10 for numbers written in scientific notation. Note: TI calculators use the EE button. Some calculators use the Exp button. If you don't know how to use these, you will waste your time and on some problems you'll get the wrong answer.

## Fact sheet: Number prefixes used in the SI system (Wikipedia)

August 26, 2010 by

0

Well organized tables showing what the number prefixes—micro, nano, mega, giga, etc—mean and how to replace them with numbers. Note: gigabyte, megabyte, kilobyte, use a slightly different meaning for the prefixes. This can be a little confusing. The Wikipedia article has a nice little discussion of the difference between that and the SI usage.

## Fact sheet: Conversion factors for changing units (Wikipedia)

August 26, 2010 by

0

Well organized tables showing conversion factors for a lot of different units. For example, if you need to know * how many feet in one kilometer * how many Newtons are in one pound * how many cubic feet are in a cubic meter Look in the table for Length for the first, the table for Force for the second, and the table for Volume, for the third, and so on.

## Fact sheet: Physical constants

August 25, 2010 by

0

Well organized tables showing the names, symbols, and magnitudes for most of the physical constants you'll ever need to us There are many physical constants in science, some of the most widely recognized being the speed of light in vacuum c, the gravitational constant G, Planck's constant h, the electric constant ε0, and the elementary charge e. Physical constants can take many dimensional forms: the speed of light signifies a maximum speed limit of the universe and is expressed dimensionally as length divided by time; while the fine-structure constant α, which characterizes the strength of the electromagnetic interaction, is dimensionless.

## Interactive java app: Zoom in by powers of ten down to the nanoscale

August 25, 2010 by

0

Interactive java app that let's you zoom in and out from the cosmic scale down to the nanoscale. Good for practicing scientific notation and Greek prefixes. View the Milky Way at 10 million light years from the Earth. Then move through space towards the Earth in successive orders of magnitude until you reach a tall oak tree and move from the actual size of a leaf into a microscopic world that reveals leaf cell walls, the cell nucleus, chromatin, DNA and finally, into the subatomic universe of electrons and protons

## Fact sheet: The Scale of things

August 24, 2010 by

0

Well organized graphic showing how large and small numbers are used to describe the real world. Shows pictures of objects along side of the order of magnitude of their sizes. Good for getting a feel for how the numbers are used and for making these small and large sizes comprehensible.