Correct Answer: B

Rationale: A balance scale is specifically designed to measure the mass of an object in grams or kilograms. It works based on the principle of balancing the unknown mass against a known mass. A thermometer is used to measure temperature, not mass, so choice A is incorrect. Choice C, 'scale,' is a bit vague and can refer to different types of scales, but a balance scale is the specific instrument used for measuring mass. Choice D, 'caliper,' is used for measuring dimensions such as length, width, or thickness, not mass.

Correct Answer: A

Rationale: To find the product of 0.5 and 20, you multiply them together. 0.5 x 20 = 10. This calculation involves multiplying a decimal (0.5) by a whole number (20). Choice A, '10', is the correct answer. Choice B, '15', is incorrect as it does not accurately represent the result of multiplying 0.5 by 20. Choices C and D, '20' and '25', are also incorrect as they do not reflect the correct calculation. This question assesses your ability to perform basic arithmetic operations involving decimals and whole numbers.

Correct Answer: A

Rationale: To convert 0.875 to a fraction, we write it as 875/1000. Simplifying by dividing both the numerator and denominator by 125, we get 7/8. Therefore, the correct answer is A. Choice B (8/7) is incorrect as it represents a fraction greater than 1. Choice C (3/4) and Choice D (9/10) do not match the correct conversion of 0.875.

Correct Answer: A

Rationale: The correct answer is A: 9. To find the result of multiplying 0.15 by 60, you simply multiply the two numbers together. 0.15 * 60 = 9. This calculation involves basic multiplication. Choices B, C, and D are incorrect as they do not reflect the correct product of 0.15 and 60. Understanding how to multiply decimals and whole numbers is essential in various real-life scenarios such as calculating percentages or adjusting measurements.

Correct Answer: B

Rationale: To convert milliliters to liters, you need to divide by 1000 since there are 1000 milliliters in a liter. Therefore, 250 milliliters is equal to 250/1000 = 0.25 liters. Choice A, 25 liters, is incorrect as it is a magnitude higher than the correct answer. Choice C, 2.5 liters, is also incorrect as it is 10 times greater than the correct conversion. Choice D, 0.025 liters, is incorrect as it is a magnitude lower than the correct conversion.