Answer: 0.0000003
Step-by-step explanation:
Think of the 3 as 3.0
The exponent -7 tells us to move the decimal point in 3.0 exactly seven spots to the left to arrive at 0.0000003
There are 6 zeros between the decimal point and the 3 in the final answer.
This very small number is read out as "3 ten millionths".