The multiples of
$\,2\,$ are $\,2\,$, $\,4\,$, $\,6\,$, $\,8\,$, $\,10\,$, $\,12\,$, $\,14\,$, $\,16\,$, $\,18\,$, and so on.
Notice that the multiples of
$\,2\,$ are obtained by taking the number $\,2\,$,
and multiplying successively by $\,1\,$, $\,2\,$, $\,3\,$, $\,\ldots\,$
Notice also that $\,2\,$ goes into each of these numbers evenly.
The multiples of
$\,3\,$ are $\,3\,$, $\,6\,$, $\,9\,$, $\,12\,$, $\,15\,$, $\,18\,$, $\,21\,$, $\,24\,$, $\,27\,$, and so on.
Notice that the multiples of
$\,3\,$ are obtained by taking the number $\,3\,$,
and multiplying successively by $\,1\,$, $\,2\,$, $\,3\,$, $\,\ldots\,$
Notice also that $\,3\,$ goes into each of these numbers evenly.
In general, the multiples of a number
$\,\,x\,\,$ are
$\,\,x\,$, $\,\,2x\,$, $\,\,3x\,$, $\,\,4x\,$, and so on.
To test if something is a multiple of
$\,\,x\,$,
just see if $\,\,x\,\,$ goes into it evenly.