2e-8 means?
If it is a calculator output it probably means
$$2e-8=2*10^{-8}$$
otherwise maybe it means
$${\mathtt{2}}{\mathtt{\,\times\,}}{{\mathtt{e}}}^{-{\mathtt{8}}} = {\mathtt{0.000\: \!670\: \!925\: \!255\: \!805}}$$