Question 1: Round 0.00456789 to 2 significant figures.

Answer: 0.0046

Question 2: Round 98765 to 2 significant figures.

Answer: 99000

Question 3: Round 0.00023456 to 2 significant figures.

Answer: 0.00023

Question 4: Round 3.14159 to 2 significant figures.

Answer: 3.1

Question 1: A car travels 1234 km and the distance is rounded to 2 significant figures for reporting. What is the rounded distance, and why is this important in scientific communication?

Answer: The distance is 1200 km. Rounding to 2 sf simplifies the number but maintains significant information, ensuring consistent and accurate communication of scale.

Question 2: A scientist measures a value as 0.056789. They report this as 0.057. Is this correct rounding to 2 sf? Explain your answer.

Answer: Yes, because 0.056789 rounded to 2 sf is 0.057. The third digit is 6, so the second digit increases by 1.

Question 3: A value is given as 7.891, but a mistake is made and it is reported as 7.9. Is this an appropriate rounding to 2 sf? Explain why or why not.

Answer: No, because 7.891 rounded to 2 sf should be 7.9, but the original value is closer to 7.89. Rounding should be consistent, and 7.9 is acceptable, but it’s better to write 7.9 only if precision is not critical.

Question 1: A recipe calls for 0.03567 liters of vanilla extract. Round this to 2 significant figures for easy measurement.

Answer: 0.036

Question 2: A sports car accelerates from 0 to 100 km/h in 8.567 seconds. Report this time rounded to 2 significant figures.

Answer: 8.6

Question 3: A stock price is $1234.5678. Round to 2 significant figures for reporting in a summary.

Answer: 1200

Question 1: Estimate the value of π to 2 significant figures and explain the process of rounding π from its known value.

Answer: π ≈ 3.14. The known value of π is 3.14159265. Rounding to 2 sf involves keeping the first two non-zero digits, so 3.14.

Question 2: Identify and correct the mistake: A student reports the value 0.00456789 as 0.0456 when rounding to 2 sf.

Answer: The mistake is in rounding. 0.00456789 rounded to 2 sf is 0.0046, not 0.0456. The correct process is to identify the first two significant non-zero digits.

Question 1: A calculator displays 0.00078912. A student reports this as 0.00078. Is this correct? Why or why not?

Answer: No, because 0.00078912 rounded to 2 sf is 0.00079. The second significant digit is 9, so the number should be rounded up.

Question 2: A student claims that 0.006789 should be rounded to 0.0068 to 2 sf. Is this correct? Explain.

Answer: Yes, because 0.006789 rounded to 2 sf is 0.0068. The third digit (7) warrants increasing the second digit (6) by 1.