All these can be done without a calculator by taking the factors of ten separately. We count zeros for the exponents.
[tex]770,000,000 / 1,100 = \dfrac{ 77 \times 10^7 }{11 \times 10^2} = 7 \times 10^5 = 700,000[/tex]
[tex]3,900,000,000 / 13,000 = \dfrac{39 \times 10^8}{13 \times 10^3} = 3 \times 10^5 = 300,000[/tex]
I'll leave the rest for you or someone else, sorry.
