How do you convert kilometers into millimeters?

[latex]1 \cm = 10 \ mm \\ \\ 10 \ cm = 10 *10 \ mm =100 \ mm \\ \\ 100 \ cm = 100 *10\ mm = 1 \ 000 \ mm\\ \\100 \ cm = 1 m \\\\ 1 \ km = 1 \ 000 \ m = 1 \ 000 * 1000 \ mm =1 \ 000 \ 000 \ mm[/latex]

there is a very simple answer. khdmdcm k for king or kilometer h for Henry or hectometer d for died or decameter m for Monday or meter d for drinking or decimeter c for chocolate or centimeter m for milk or millimeter. to get bigger move the decimal over to the left how many places you have to. to get smaller move the decimal to the right as many places as you have to. hope I helped