what is 1.9891x10 to the 30th power divided by 1.9008x10 to the 27th power

$$\frac{1.9891\times 10^{30}}{1.9008\times 10^{27}}=\frac{1.9891\times 10^{30-27}}{1.9008}=\frac{1.9891\times 10^3}{1.9008}=\frac{1989.1}{1.9008}$$

$${\frac{{\mathtt{1\,989.1}}}{{\mathtt{1.900\: \!8}}}} = {\mathtt{1\,046.454\: \!124\: \!579\: \!124\: \!579\: \!1}}$$

do it on the site calc - on the home page.

you could enter it like this (this is just one way to enter it, there are others)

(1.9891x10^30)/(1.9008x10^27)