Title: Show What You Know: Scientific Notation for Integrated Energy
Course: Open MAT107 Contextualized > Section: Powers of Ten and Scientific Notation

Q: The national debt is about $

What is this number in standard form?
- $13,040,000,000,000 (Yes, that is over 13 trillion dollars. And it is probably a lot more by now.)
- $1,304,000,000 (Make sure you count 13 places from the decimal point to the right.)
- $130,040,000,000,000 (You only move 13 places from the decimal point, not from the left of the 1. You added an extra zero.)
A: $13,040,000,000,000

Q: The nearest star to ours (the Sun) is Proxima Centauri at a distance of about

24,700,000,000,000 miles.

What is this number in scientific notation?
- 2.47 times 10 to the power of 13 (Correct!)
- 24.7 times 10 to the power of 12 (No, the number has to be between 1 and 10.)
- .247 times 10 to the power of 14 (No, the number needs to be between 1 and 10.)
A: 2.47 times 10 to the power of 13

Q: The length of a typical virus cell is meters.

What is this number in standard form?
- 0.000000075 (You are correct!)
- 750,000,000 (Because the exponent is negative, the number is getting smaller. You need to move your decimal to the left.)
- 0.00000075 (You needed to move your decimal one more space.)
A: 0.000000075

Q: You purchased a solar PV (photovoltaic) system for your home.   You paid $72,000 for the system at $10.99/watt.   What array size, in kilowatts, did you purchase?
- Approximately 6.551 kW (That is correct!)
- 6551.41 kW (No, that would be the number of watts. But you need to move the decimal point three places to the left to turn the number into kilowatts.)
A: Approximately 6.551 kW

Q: You purchased a solar PV (photovoltaic) system for your home.   You paid $67,890 for an array size of 8.1kW.   How much did you pay per watt?
- $8.38/watt (Correct!)
- $8381.48 (When you did your division you figured out how much you paid per kilowatt. You need to take that number and move the decimal point 3 places to the left so that it represents watts.)
A: $8.38/watt