Technique for Conversions

We offer what we feel to be the best way to perform conversions described using excrutiating "baby steps" for all our math-challenged friends. Once you get the hang of this, showing your work will be much harder than doing these in your head.

Step 1: identify the conversion equation. (Choose one from the conversion chart)
      Explanation: the equation should contain both units invloved in the conversion.
      Examples: 1 Kg = 2.2 lbs    OR    1 grain = 60 mg.

Step 2: make a fraction that equals 1.
      Explanation: realize that the left and right sides of the conversion equation are the same numeric value stated in different units AND anything divided by itself equals 1, then make the fraction using these equivalent values.
      Examples:
	The equation (1 Kg = 2.2 lbs) yields:
		 1 Kg			2.2 lbs
	either	------- = 1	or	------- = 1
		2.2 lbs			 1 kg

	While the equation (1 grain = 60 mg) yields:
		1 grain			 60 mg
	either	------- = 1	or	------- = 1
		 60 mg			1 grain
You got it! Each of those fractions equals 1 and is called the conversion factor.

Step 3: choose the most appropriate conversion factor.
      Explanation: realize that the units in the numerator will be preserved and the units in the denominator will be cancelled out. So choose the fraction that has the units you want keep in its numerator. Or choose the fraction that has the units to convert in its denominator. Either way you think about it, it will be the same fraction.
      Examples:
To convert lbs to kg use:	To convert kg to lbs use:
	 1 Kg				2.2 lbs
	-------				-------
	2.2 lbs				 1 Kg

To convert grains to mg use:	To convert mg to grains use:
	 60 mg				1 grain
	-------				-------
	1 grain				 60 mg
Step 4: do the conversion.
      Explanation: Simply multiply the number to be converted by the conversion factor, cancelling as you go. (Hint: multiply the value to be converted by the numerator of the conversion factor.)
      Examples:
(Choose a conversion factor from Step 3 above.)
1) Convert 132 lbs to kg.
	First, set up the fraction like this:
		 (1 kg)	   (132 lbs)(1 kg)
       (132 lbs) ------- = ---------------
		 2.2 lbs       2.2 lbs

See how lbs will cancel out, and kg will be preserved?

	Then multiply it out, cancelling as you go:
	132 kg
	------ = 60 kg
	  2.2

2) Now done faster: Convert 80 kg to lbs.
	(80kg)(2.2 lbs)   176 lbs
	--------------- = ------- = 176 lbs
	      1 kg	     1

Can you recognize the conversion factor
 on the left side of the above equation?

3) Now one using grains: Convert 7.5 grains to mg.
	(7.5 grains)(60 mg)  450 mg
	------------------ = ------ = 450 mg
	      1 grain	        1


4) Last one: Convert 120 mg to grains.
	(120 mg)(1 grain)   120 grain
	----------------- = --------- = 2 grains
	      60 mg	       60