Correct Answer: B

Rationale: To convert meters to millimeters, you need to multiply by 1,000 because there are 1,000 millimeters in a meter. Therefore, 3.45 meters 1,000 = 3,450 millimeters. Choices A, C, and D are incorrect because they do not reflect the correct conversion factor from meters to millimeters.

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, 3.54 mm · 1,000 = 0.00354 meters. Choice A (0.0354 m) is incorrect as it is 10 times the correct conversion. Choice C (35.4 m) is incorrect as it would be the equivalent of 35,400 millimeters. Choice D (0.035 m) is also incorrect as it is 100 times greater than the correct conversion.

Correct Answer: B

Rationale: The calculation of 0.4 divided by 40 results in 0.01, which can be expressed as 1/100. This fraction is the correct representation of the division of 0.4 by 40. Choice A, 1/100, is the correct answer as it accurately reflects the division. Choices C and D, 1/400 and 1/40000 respectively, do not correctly represent the division operation performed on 0.4 and 40, leading to incorrect results and are therefore not the correct answers.

Correct Answer: A

Rationale: To convert grams to milligrams, you multiply by 1000 since there are 1000 milligrams in a gram. Therefore, to convert 0.04 grams to milligrams, you would do 0.04 * 1000 = 40 mg. Choice A, '40 mg,' is the correct answer. Choices B, C, and D are incorrect because they do not correctly convert grams to milligrams. Choice B, '400 mg,' is incorrect because it mistakenly multiplies by 10 instead of 1000. Choice C, '4 mg,' is incorrect because it does not account for the correct conversion factor. Choice D, '0.4 mg,' is incorrect because it underestimates the conversion by a factor of 10.

Correct Answer: B

Rationale: To convert liters to milliliters, you need to multiply by 1000, not 10000. Therefore, 0.2 liters equals 200 ml (0.2 x 1000 = 200 ml). Choice A, 20 ml, is incorrect because it's the result of multiplying by 10 instead of 1000. Choice C, 2 ml, is incorrect as it's the result of ignoring the decimal point. Choice D, 2000 ml, is incorrect because it's the result of multiplying by 10000.