Answer
253,000,000
Work Step by Step
We are asked to find an estimate and an exact value. To do this, we round each number until they are easy to multiply in our head for the estimate. We then use the calculator to find the exact number. Doing this, we find:
$$ 600,000,000-300,000,000 = 300,000,000 $$
The exact value is:
$$ 578,000,000-325,000,000 = 253,000,000$$
