Number ToolkitEdexcel IGCSE Maths: Subtopic test

1. 1
   A weather station records overnight temperatures for a scientific study. At midnight the temperature in Reykjavik was $-7$ degrees Celsius, and at midnight in Ottawa it was $-13$ degrees Celsius.

   (a)

   At midnight the temperature in Reykjavik was $-7$ degrees Celsius. By 9am it had risen by $11$ degrees. What was the temperature at 9am?

   [1 mark]

   • A$4$ degrees Celsius
   • B$-4$ degrees Celsius
   • C$18$ degrees Celsius
   • D$-18$ degrees Celsius

   (b)

   What is the difference between the midnight temperature in Ottawa ($-13$ degrees Celsius) and the midnight temperature in Reykjavik ($-7$ degrees Celsius)?

   [1 mark]

   • A$20$ degrees Celsius
   • B$-6$ degrees Celsius
   • C$6$ degrees Celsius
   • D$-20$ degrees Celsius

   (c)

   Which of the following calculations correctly evaluates $(-4) \times (-3) + (-2)$ using BIDMAS?

   [1 mark]

   • A$-10$
   • B$10$
   • C$14$
   • D$-14$

   Total for question 1: 3 marks

2. 2
   A caterer is preparing an invoice for a wedding using standard units of mass and money. She buys napkins, cups and a joint of meat for the event.

   (a)

   A caterer buys 8 boxes of napkins at 3 dollars 45 cents each and 5 packs of cups at 2 dollars 19 cents each. Calculate the total cost.

   [2 marks]

   (b)

   The caterer also buys a joint of meat with mass 2.4 kilograms at 9 dollars 50 cents per kilogram. She rounds her total invoice (napkins, cups and meat) to the nearest dollar. What is the rounded total?

   [2 marks]

   Total for question 2: 4 marks

3. 3
   A warehouse manager is checking a delivery of tins of paint and needs to plan a lorry journey to distribute them, working with masses and journey times given in the 24-hour clock.

   (a)

   A warehouse manager is checking a delivery of 240 identical tins of paint, each with mass 1.35 kg. Calculate the total mass of the delivery in kilograms, then convert your answer to tonnes (1 tonne = 1000 kg).

   [3 marks]

   (b)

   The delivery lorry leaves the warehouse at 21:45 and the journey to the retail store takes 2 hours and 50 minutes, including one stop. If the lorry stops for 15 minutes during the journey, at what time (24-hour clock) does it arrive at the store?

   [3 marks]

   Total for question 3: 6 marks

4. 4
   A school stationery cupboard is being restocked. The school orders 936 pens, packs them into boxes of 24, and calculates the total spend including a discount applied using BIDMAS rules on the invoice formula.

   (a)

   A school is ordering pens for a stationery cupboard. The number 936 is the total number of pens ordered. State whether 936 is odd or even, and list all the factors of 936 that are prime numbers.

   [4 marks]

   (b)

   The 936 pens are packed into boxes of 24. Using directed numbers, if 3 boxes are later found damaged and returned (a change of $-3 \times 24$ pens), how many undamaged pens remain?

   [4 marks]

   (c)

   The invoice formula for the total cost in dollars is $C = 2 \times (24 - 4) + 15 \div 3$ multiplied by the number of boxes remaining (36, after the damaged ones are excluded). Evaluate $C$ using BIDMAS, then find the total invoice cost for 36 boxes.

   [5 marks]

   Total for question 4: 13 marks

End of questions