Question 1: Round 3.76 to 1 decimal place.

Answer: 3.8

Question 2: Round 5.04 to 1 decimal place.

Answer: 5.0

Question 3: Calculate the upper bound of 7.2 when rounded to 1 decimal place.

Answer: 7.25

Question 4: Calculate the lower bound of 2.9 when rounded to 1 decimal place.

Answer: 2.85

Question 5: A measurement is recorded as 12.3. What is the range of possible true values if rounded to 1 decimal place?

Answer: 12.25 to 12.35

Question 6: A length is rounded to 1 decimal place as 4.5. What are the maximum and minimum possible actual lengths?

Answer: Maximum: 4.55; Minimum: 4.45

Question 7: Construct a triangle on the grid with side lengths rounded to 1 decimal place as 3.2, 4.5, and 5.1. What are the possible ranges for each side length?

Answer: Side 1: 3.15 to 3.25; Side 2: 4.45 to 4.55; Side 3: 5.05 to 5.15

Question 8: A car's average speed is recorded as 65.2 km/h. What is the possible actual speed range if rounded to 1 decimal place?

Answer: Speed range: 65.15 km/h to 65.25 km/h

Question 9: A store records an average transaction value as £12.7 (rounded to 1 dp). What is the true range of transaction values?

Answer: £12.65 to £12.75

Question 10: Two measurements are 8.4 and 8.6, both rounded to 1 decimal place. Are these measurements necessarily equal? Explain.

Answer: No, because 8.4 could be from 8.35–8.44 and 8.6 from 8.55–8.64, so they may not be equal.

Question 11: A measurement of 9.8 is rounded to 1 dp. What is the precise range of possible true values?

Answer: 9.75 to 9.85

Question 12: Identify and correct the mistake: A student states that 2.3 rounded to 1 dp is 2.4.

Answer: Incorrect; 2.3 rounded to 1 dp is 2.3, not 2.4.