# How do you add 7.8 x 10^6 +1.65 x 10^6?

Since the $10$powers are the same, you can just add the numbers:
$7.8 \cdot {10}^{6} + 1.65 \cdot {10}^{6}$
$= \left(7.8 + 1.65\right) \cdot {10}^{6}$
$= 9.45 \cdot {10}^{6}$