1. 1
   A machinist measures the length of a metal rod using digital vernier callipers. The reading is $12.376$ cm.

   (a)

   Round $12.376$ cm to 2 decimal places.

   [1 mark]

   • A$12.38$ cm
   • B$12.37$ cm
   • C$12.4$ cm
   • D$12.376$ cm

   (b)

   Round $12.376$ cm to 3 significant figures.

   [1 mark]

   • A$12.3$ cm
   • B$12.4$ cm
   • C$12.37$ cm
   • D$123$ cm

   (c)

   Round $12.376$ cm to the nearest whole number of centimetres.

   [1 mark]

   • A$13$ cm
   • B$12$ cm
   • C$12.4$ cm
   • D$12.0$ cm

   Total for question 1: 3 marks

2. 2
   A stationery shop sells notebooks at £3.87 each. A teacher buys 19 notebooks for her class.

   (a)

   By rounding each number to 1 significant figure, work out an estimate for the total cost of the notebooks.

   [2 marks]

   (b)

   A calculator gives the exact total cost of the notebooks as £73.53. Using your estimate from part (a), explain whether this answer is reasonable.

   [2 marks]

   Total for question 2: 4 marks

3. 3
   The length of a school corridor is given as 24 m, correct to the nearest metre.

   (a)

   Write down the error interval for the true length, $l$ metres, of the corridor, using inequality notation.

   [3 marks]

   (b)

   The corridor is to be covered by carpet tiles laid end to end in a single row along its length. Each tile is exactly 0.5 m long. Using the upper bound of the corridor's true length, calculate the greatest possible number of whole tiles that could fit along the corridor.

   [3 marks]

   Total for question 3: 6 marks

4. 4
   A cyclist travels a distance of 15 km, measured to the nearest km, in a time of 42 minutes, measured to the nearest minute.

   (a)

   Calculate the upper bound for the cyclist's average speed, in km/h, giving your answer correct to 3 significant figures.

   [4 marks]

   (b)

   Calculate the lower bound for the cyclist's average speed, in km/h, giving your answer correct to 3 significant figures.

   [4 marks]

   (c)

   Using your unrounded values from parts (a) and (b), show that the difference between the upper and lower bounds for the cyclist's average speed is greater than $1.5$ km/h.

   [5 marks]

   Total for question 4: 13 marks

End of questions