Convert 345,000 millimeters to centimeters (cm).

Correct Answer: B

Rationale: To convert millimeters to centimeters, you need to divide by 10 since there are 10 millimeters in 1 centimeter. Therefore, 345,000 mm · 10 = 34,500 cm. Choice A is incorrect because it is a factor of 10 higher than the correct answer. Choice C is incorrect because it represents the original quantity in centimeters, not the converted value. Choice D is incorrect as it erroneously multiplies the millimeters by 1,000 instead of dividing by 10 to convert to centimeters.

Correct Answer: B

Rationale: To convert kilograms to grams, you need to multiply by 1,000 since there are 1,000 grams in a kilogram. Therefore, 35.40 kg 1,000 = 35,400 grams. Choice A (354 g) is incorrect because it is off by a factor of 10. Choice C (3,540 g) is incorrect as it is off by a factor of 100. Choice D (3.54 g) is incorrect as it represents kilograms instead of grams.

Correct Answer: B

Rationale: To convert millimeters to meters, you need to divide by 1,000 since there are 1,000 millimeters in a meter. Therefore, 354,000 mm · 1,000 = 354 meters. Choice A, '354 m,' is correct as it represents the converted value. Choice C, '354,000 km,' is incorrect as it suggests converting to kilometers instead of meters. Choice D, '35,400 m,' is incorrect as it is not the result of the correct conversion calculation.

Correct Answer: A

Rationale: Density is measured in grams per cubic meter (g/m³) in the metric system. This unit represents the amount of mass (in grams) per unit volume (cubic meter). Choice B, grams per liter (g/L), is incorrect as density is not typically measured in liters. Choice C, grams per cubic centimeter (g/cm³), is a common unit for density but not the standard SI unit. Choice D, grams per square meter (g/m²), is a unit for surface density, not volumetric density. Therefore, the correct unit for measuring density in the metric system is grams per cubic meter (g/m³).

Correct Answer: B

Rationale: The metric system is based on powers of 10. This means that units within the system are related by factors of 10, making conversions straightforward by simply shifting the decimal point. The system's simplicity and consistency are derived from this fundamental concept. Choices A, C, and D are incorrect because the metric system's foundation lies in the consistent relationship between units through powers of 10, not through basic arithmetic operations like multiplication, addition, or subtraction.