Math

This is th same as asking   " how many times does  2 x 10^-7   go in to 4 x 10^-6 ? "

=20 times smaller

$2\times 10-7=20=13$

$4\times 10-6=40-6=34$

Therefore, it is $34-13=21$ and $\frac{21}{13}$ times smaller.

You are very welcome!

:P