Mastering Scientific Notation: Subtraction & Multiplication

A scientist measures the mass of a small asteroid as 3.2 x 10^12 kg. After further analysis, she finds that the mass is actually 2.5 x 10^12 kg. What is the difference in mass between the two measurements?

• 1.5 x 10^12 kg

• 2.0 x 10^12 kg

• 4.0 x 10^11 kg

• 7.0 x 10^11 kg

A bacteria culture grows at a rate of 1.5 x 10^6 cells per hour. If the culture is observed for 4 hours, how many cells will be present at the end of that time?

• 1.5 x 10^6 cells

• 6.0 x 10^6 cells

• 3.0 x 10^6 cells

• 4.5 x 10^6 cells

The distance from Earth to a nearby star is approximately 4.2 x 10^16 meters. If a spaceship travels 1.5 x 10^15 meters towards the star, how far is it from the star now?

• 4.05 x 10^16 meters

• 3.9 x 10^16 meters

• 4.5 x 10^16 meters

• 4.0 x 10^16 meters

A researcher is studying a rare species of plant that has a height of 2.3 x 10^2 cm. If another plant of the same species is found to be 1.8 x 10^2 cm tall, what is the height difference between the two plants?

• 50 cm

• 70 cm

• 100 cm

• 30 cm

A comet is traveling at a speed of 5.0 x 10^4 km/h. If it travels for 3 hours, how far will it have traveled in kilometers?

• 120000 km

• 180000 km

• 150000 km

• 200000 km

The volume of a small lake is estimated to be 1.2 x 10^9 cubic meters. If a drought reduces the volume by 3.5 x 10^8 cubic meters, what is the new volume of the lake?

• 9.0 x 10^8 cubic meters

• 8.5 x 10^8 cubic meters

• 1.0 x 10^9 cubic meters

• 7.5 x 10^8 cubic meters

A satellite orbits Earth at an altitude of 3.6 x 10^7 meters. If it descends to an altitude of 2.1 x 10^7 meters, how much altitude has it lost?

• 2.5 x 10^7 meters

• 3.0 x 10^7 meters

• 1.5 x 10^7 meters

• 1.2 x 10^7 meters

A factory produces 2.5 x 10^3 toys per day. If the factory operates for 15 days, how many toys will it produce in total?

• 3.75 x 10^4

• 2.5 x 10^4

• 3.0 x 10^3

• 1.5 x 10^5

The population of a small town is approximately 1.8 x 10^4 people. If 2.5 x 10^3 people move away, what is the new population of the town?

• 13000

• 18000

• 15500

• 20000

A chemical reaction produces 4.0 x 10^5 grams of a substance. If 1.2 x 10^5 grams are used in an experiment, how much of the substance remains?

• 4.0 x 10^5 grams

• 3.0 x 10^5 grams

• 1.0 x 10^5 grams

• 2.8 x 10^5 grams