# Is there a site to do conversions of measurements

1. Apr 18, 2005

### zy

Is there a site that teaches how to do conversions of measurments. More specificly I need one that teaches coversion between different measurements like gallons to cubic inches or square feet to millimeters or grams to meters LOL if there is such a thing lol

2. Apr 18, 2005

### OlderDan

I stongly believe that all conversions should be taught as multiplication of a given quantity by the identity, 1. There are countless ways to write 1 as the ratio of any two equals. For example to convert feet to inches

$$3 feet = 3 feet * \frac{12 inches}{1 foot} = 36 inches$$

This can be extended to changes of measuring systems

$$3 feet = 3 feet * \frac{12 inches}{1 foot} * \frac{2.54 cm}{1 inch} = 91.44 cm$$

All conversions can be done by multiplying by appropriate representations of 1. One should never have to think about when to divide and when to multiply. The units tell us which way to form the numerator and denominator of the fraction equal to 1.

Last edited: Apr 18, 2005
3. Apr 18, 2005

### zy

Cool I get how to go from say grams to kilograms Its just when it goes from one measurement like grams to say liters. They boggles the mind LOL.

4. Apr 18, 2005

### KC6794

5. Apr 18, 2005

### zy

Wow thats a nice site but it does not teach it. I would have to sneak that in and cheat on my math test LOL And I dont have time to memorize 800 conversions LOL

6. Apr 18, 2005

### OlderDan

I hate tables like the one posted. I would avoid any table that has no equal signs I want to see

2.54 cm = 1 inch
1 mile = 5280 feet
1 liter = 1000 cm^3

etc etc etc

7. Apr 18, 2005

### OlderDan

Grams to liters only makes sense if you know the density of a substance involved. Then you form a conversion fraction from a known ratio.

mass = density * volume

For water density = 1 gm/cm^3

mass of water = (1gm/cm^3)*volume of water

8. Apr 18, 2005

### zy

Ok thanks everyone. I will check back in several hours and see if anyone has any more tips. Thanks for the help. Off to bed I go! :)