3.8*10 to the power of 8 m/s / 1.2*10 to the power of 15

3.8*10⁸/1.2*10¹⁵ = (3.8/1.2)*10⁸*10^-15 = (3.8/1.2)*10^8-15 = (3.8/1.2)*10^-7

$$\left({\frac{{\mathtt{3.8}}}{{\mathtt{1.2}}}}\right){\mathtt{\,\times\,}}{{\mathtt{10}}}^{\left(-{\mathtt{7}}\right)} = {\mathtt{0.000\: \!000\: \!316\: \!666\: \!666\: \!7}}$$

or  $$3\frac{1}{6}*10^{-7}$$

Oh, I see how you did that Alan.

Forget my old answer.