Question

In 1867, the United States purchased Alaska from Russia. Alaska is about 5.9 × 105 square miles. The United States paid about $12.20 per square mile. Approximately how much did the United States pay Russia for Alaska?

Complete the steps to answer the question.

1. Write the expression:       (5.9 × 105)(12.2)

2. Multiply the decimal values:     
× 105

3. Write in scientific notation:     
×

The United States paid Russia approximately
$7,200,000
for Alaska.

Answer 1

Let's go through the steps to find out how much the United States paid Russia for Alaska.

1. The expression we need to evaluate is:
\[
(5.9 \times 10^5)(12.2)
\]

2. Next, we will multiply the decimal values \(5.9\) and \(12.2\):
\[
5.9 \times 12.2 = 71.98
\]

3. Now we multiply by \(10^5\):
\[
71.98 \times 10^5
\]

4. To write the expression in proper scientific notation, we need to express \(71.98\) as \(7.198 \times 10^1\) (since \(71.98 = 7.198 \times 10^1\)). Now we combine this with \(10^5\):
\[
(7.198 \times 10^1) \times 10^5 = 7.198 \times 10^{1+5} = 7.198 \times 10^6
\]

To find the approximate value, we can convert \(7.198 \times 10^6\) to a normal number:
\[
7.198 \times 10^6 = 7,198,000
\]

Therefore, the United States paid Russia approximately **$7,200,000** for Alaska.