Expert: Josh - 7/20/2003

Question
500 g is equivalent to:  one pound or 5 kilograms or 0.5kg or 0.05kg =  ? Your help would be great, Thankyou.

Answer
Hi Doug,

The answer is 0.5kg, since there are 1000 grams per kilogram (Kg). The prefix "kilo" (K) is recognized as a multiplier. Every time you see this, you automatically increase the ordinary figure by a factor of one thousand.

This is the beauty of the metric system. Each unit advances by multiples of ten. This idea is illustrated in the table below.

1 One
10 Ten          (factor of 10 relative to unit 1)
100 Hundred     (factor of 100 relative to unit 1)
1000 Thousand   (factor of 1000 relative to unit 1)
1000000 Million     (factor of 1000000 rel.to unit 1)
1000000000 Billion  (factor of 1000000000 rel.to unit 1) etc.

For instance if you compare one thousand (1000)
with one million (1000000), they differ by a factor of 1000.
So, one million is simply a thousand lots of thousand.

Another way to view this is by using scientific notations.
Typically, we represent a thousand 1000, by 10^3 and write
a million 1,000,000 as 10^6.

Using this superscript (^) notation, n is called the exponent. Basically, it tells us how many zeros to append to the basic figure to produce the number that we want.

eg.1, with three thousands, we have 3*10^3.
This suggests that we add three zeros after the digit 3 to yield 3000.

eg.2, if we have two million and four hundred thousands, say, we can write 2,400,000 more compactly as 2.4X10^6. In this case, we interpret 10^6 as a multiplier, and times 2.4 by a factor of a million to yield 2,400,000.

Cheers,
Josh