Mastering Subtraction in Scientific Notation: Grade 8 Quiz

A scientist measures the height of a mountain as 4.5 x 10^3 meters. Another mountain is measured at 3.2 x 10^3 meters. What is the difference in height between the two mountains in scientific notation?

• 2.3 x 10^3 meters

• 1.3 x 10^3 meters

• 4.0 x 10^3 meters

• 1.2 x 10^3 meters

A comet is traveling at a speed of 2.5 x 10^4 kilometers per hour. If it slows down to 1.8 x 10^4 kilometers per hour, how much has its speed decreased?

• 0.5 x 10^4 kilometers per hour

• 1.0 x 10^4 kilometers per hour

• 0.7 x 10^4 kilometers per hour

• 2.0 x 10^4 kilometers per hour

The population of a small town is approximately 1.2 x 10^5 people. If 3.5 x 10^4 people move away, what is the new population in scientific notation?

• 1.0 x 10^5

• 9.0 x 10^4

• 7.5 x 10^4

• 8.5 x 10^4

A factory produces 5.6 x 10^2 toys in a day. If production increases by 2.3 x 10^2 toys, what is the total production in scientific notation?

• 7.9 x 10^2

• 6.5 x 10^2

• 5.3 x 10^2

• 8.2 x 10^2

A researcher finds that a certain bacteria can double its population every 3 hours. If the initial population is 1.5 x 10^3, what will the population be after 6 hours in scientific notation?

• 12.0 x 10^3

• 6.0 x 10^3

• 3.0 x 10^3

• 1.2 x 10^4

A car travels 3.0 x 10^2 kilometers on a full tank. If it uses 1.2 x 10^2 kilometers worth of fuel for a trip, how much distance can it still cover in scientific notation?

• 3.0 x 10^2 kilometers

• 1.8 x 10^2 kilometers

• 1.0 x 10^2 kilometers

• 2.4 x 10^2 kilometers

A satellite orbits the Earth at an altitude of 4.0 x 10^4 meters. If it descends to an altitude of 2.5 x 10^4 meters, what is the change in altitude in scientific notation?

• 1.0 x 10^4 meters

• 2.0 x 10^4 meters

• 3.5 x 10^4 meters

• 1.5 x 10^4 meters

A library has 2.5 x 10^6 books. If 1.2 x 10^5 books are checked out, how many books remain in the library in scientific notation?

• 2.0 x 10^6

• 2.5 x 10^6

• 2.38 x 10^6

• 1.2 x 10^5

A smartphone has a battery capacity of 3.0 x 10^3 milliamp hours. If it uses 1.5 x 10^2 milliamp hours for a video call, how much battery capacity is left in scientific notation?

• 2.85 x 10^3 mAh

• 3.0 x 10^2 mAh

• 2.5 x 10^3 mAh

• 1.5 x 10^3 mAh

A space probe travels 6.4 x 10^7 kilometers to reach a distant planet. If it has already traveled 2.1 x 10^7 kilometers, how much further does it need to go in scientific notation?

• 4.3 x 10^7 kilometers

• 3.5 x 10^7 kilometers

• 2.0 x 10^7 kilometers

• 5.0 x 10^7 kilometers