c. $\left(8 \times 10^{9}\right) \div\left(4 \times 10^{6}\right)=$ (Use the multiplication symbol in the math palette as needed.)

Step 1 ：\((8 \times 10^9) \div (4 \times 10^6) = (8 \times 10^9) \cdot \frac{1}{4 \times 10^6}\)

Step 2 ：\((8 \times 10^9) \cdot \frac{1}{4 \times 10^6} = 8 \cdot 10^9 \cdot \frac{1}{4} \cdot \frac{1}{10^6}\)

Step 3 ：\(8 \cdot 10^9 \cdot \frac{1}{4} \cdot \frac{1}{10^6} = 8 \cdot \frac{1}{4} \cdot 10^9 \cdot \frac{1}{10^6}\)

Step 4 ：\(8 \cdot \frac{1}{4} \cdot 10^9 \cdot \frac{1}{10^6} = (8 \div 4) \cdot (10^9\div 10^6)\)

Step 5 ：\((8\div 4) \cdot (10^9 \div 10^6) = 2 \cdot 10^3\)

Step 6 ：\(2 \cdot 10^3 = \boxed{2000}\)