(9.09x10to the 8 power)-[(6.33x10to the 9th power)]x(4.06x10to the -7power)] =

$$\\(9.09\times 10^8 )-(6.33\times 10^9\times 4.06\times 10^{-7}) =\\\\
(9.09\times 10^8 )-(6.33\times 4.06 \times 10^9\times 10^{-7}) =\\\\
(9.09\times 10^8 )-(25.6998 \times 10^{9-7}) =\\\\
(9.09\times 10^8 )-(25.6998 \times 10^{2}) =\\\\
(9.09\times 10^8 )-2569.98 =\\\\$$$$$$

$${\mathtt{9.09}}{\mathtt{\,\times\,}}{{\mathtt{10}}}^{{\mathtt{8}}}{\mathtt{\,-\,}}{\mathtt{2\,569.98}} \approx {\frac{-{\mathtt{1\,794\,768\,755}}}{{\mathtt{50}}}} \approx {\mathtt{908\,997\,430.02}}$$

That minus sign in the calculator working should not be there.  It's a glitch in the calculator

~ -2.12 X 10^11.