Subtracting in Scientific Notation: Real-World Problems

A scientist measures the mass of a small asteroid as 3.2 x 10^6 kg. After a collision, the mass decreases by 1.5 x 10^5 kg. What is the new mass of the asteroid in scientific notation?

• 3.05 x 10^6 kg

• 3.0 x 10^6 kg

• 2.8 x 10^6 kg

• 3.7 x 10^6 kg

A researcher finds that a certain bacteria population is 2.5 x 10^4. After a week, the population decreases by 1.2 x 10^3 due to a treatment. What is the new population of the bacteria?

• 2.5 x 10^4

• 1.3 x 10^4

• 2.4 x 10^4

• 2.38 x 10^4

An engineer is designing a satellite that weighs 4.8 x 10^3 kg. If the satellite loses 2.1 x 10^2 kg during testing, what is its weight after the loss?

• 4.59 x 10^3 kg

• 4.5 x 10^3 kg

• 4.7 x 10^3 kg

• 4.8 x 10^2 kg

A factory produces 1.5 x 10^7 units of a product in a year. If production decreases by 3.0 x 10^6 units due to a supply chain issue, how many units are produced now?

• 1.5 x 10^7

• 1.2 x 10^7

• 2.0 x 10^7

• 1.0 x 10^7

A comet is traveling at a speed of 2.3 x 10^4 km/h. If its speed decreases by 4.5 x 10^3 km/h due to gravitational pull, what is its new speed?

• 1.5 x 10^4 km/h

• 2.0 x 10^4 km/h

• 1.85 x 10^4 km/h

• 2.8 x 10^4 km/h

A library has 5.6 x 10^5 books. If 2.3 x 10^4 books are checked out, how many books remain in the library?

• 536000

• 550000

• 500000

• 540000

A population of fish in a lake is estimated to be 1.2 x 10^6. If 3.5 x 10^5 fish are caught, what is the remaining population?

• 850000

• 900000

• 1.5 x 10^6

• 1.0 x 10^6

A smartphone manufacturer produces 3.4 x 10^5 devices in a month. If 1.1 x 10^5 devices are returned due to defects, how many devices are left?

• 2.3 x 10^5

• 2.0 x 10^5

• 3.0 x 10^5

• 1.5 x 10^5

A planet's diameter is approximately 1.2 x 10^7 meters. If a recent measurement shows a decrease of 2.5 x 10^6 meters due to erosion, what is the new diameter?

• 1.5 x 10^7 meters

• 9.5 x 10^6 meters

• 8.5 x 10^6 meters

• 1.0 x 10^7 meters

A chemical reaction produces 7.8 x 10^4 grams of a substance. If 2.2 x 10^3 grams are used in an experiment, how much of the substance remains?

• 7.58 x 10^4 grams

• 8.0 x 10^4 grams

• 2.0 x 10^3 grams

• 7.6 x 10^4 grams