Is 0.002 rational

Question

I want to know if this is an integer

 

Answer 1

An integer, also known as a 'whole number,' is a number that can be written without a fraction or a decimal.  They are the so-called counting numbers: 0, 1, 2, 3, 4, and so forth, as well as the negative equivalents, -1, -2, -3, and so forth.  As such, .002 is not an integer.

 

The rational numbers, though, are those that can be written as a fraction involving two integers.  3/4, for example, is a rational number, because 3 and 4 are both integers.  .75 is equivalent to 3/4, and is a rational number for the same reason.

 

.002 specifically can be written as 2/1000, or as 1/500.  Since 1, 2, 500, and 1000 are all integers, .002 is rational.  In fact, all terminating decimals (those that stop at some point, rather than going on forever) are rational, because they can always be written as an integer over some power of ten.