Number 4a: Mastery Questions |
| Guidance Notes - To answer each question, click on the letter that corresponds to the correct answer. You then need to click the 'Check' button to see if you are correct.
If your answer is incorrect, you will be given a hint on how to get the correct answer. You then need to click the 'Try again' button to attempt the question once more. |
| 1. |
Round 54462 to 2 significant figures.
Incorrect. Hint - Look at page 2 in Number 4a unit.
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| 2. |
Round 154.965 to 2 significant figures.
Incorrect. Hint - Look at page 2 in Number 4a unit.
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| 3. |
Which of these is the most sensible estimate for 98.6 ÷ 495?
Incorrect. Hint - Look at page 3 in Number4a unit.
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| 4. |
A plane is flying at 32000 feet. The height has been rounded to 3 significant figures.
Which of these inequalities shows the correct upper and lower bounds for the height h?
Incorrect. Hint - Look at page 4 in Number4a unit.
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| 5. |
The radius of a circle, r, is 3.2 cm rounded to 1 decimal place.
What is the lower bound of r?
Incorrect. Hint - Look at page 5 in Number4a unit.
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| 6. |
Aaron is 1.68 m tall. His height is given to 2 decimal places. Which of these inequalities shows the correct upper and lower bounds for his height,
h m?
Incorrect. Hint - Look at page 4 in Number4a unit.
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| 7. |
By rounding each number to one significant figure, estimate the value of
5.45 × 6.54 × 4.49?
Incorrect. Hint - Look at page 6 in Number4a unit.
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| 8. |
Express 144 as the product of its prime factors.
Incorrect. Hint - Look at page 10 in Number4a unit.
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| 9. |
Two numbers are written as the product of their prime factors as shown.
 22 × 3 × 5 and 2 × 3 × 7
Which of these is the lowest common multiple (LCM) of the two numbers?
Incorrect. Hint - Look at page 12 in Number4a unit.
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| 10. |
Three numbers are written as the product of their prime factors as shown.
23 × 32 ×
52 × 7 and 24 × 33 ×
52 × 72 and 23 ×
33 × 5 × 7
Which of these is the highest common factor (HCF) of the three numbers?
Incorrect. Hint - Look at page 11 in Number4a unit.
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| 11. |
What is 62 × 62?
Incorrect. Hint - Look at page 13 in Number4a unit.
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| 12. |
What is 34 × 32?
Incorrect. Hint - Look at page 13 in Number4a unit.
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| For Questions 13, 14 and 15, you will need to answer them using paper and pencil and then click the 'Check' button to see if you have done them correctly. |
13. |
3 marks – 1 for some evidence of each stage of the calculation.
42 × 53 = 2226 (1 mark for evidence of using the given answer)
43 × 53 = 2226 + 53 = 2279 (1 mark for evidence of adding either 53 or 42)
53 × 43 = 2279
54 × 43 = 2279 + 43 = 2322 (1 mark for evidence of adding either 43 or 54)
If no working shown, then no marks.
If long multiplication used also no marks.
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| 14. |
Estimate the answer to this calculation by rounding each number to 1 significnat figure.
2 marks for clear evidence of rounding all four numbers to 1 significant figure
i.e. 400 × 400200 × 100
1 mark for the correct answer of 8.
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| 15. |
A packet of screws contains 100 screws to the nearest 10.
Bryan buys 10 packets of screws and puts them in an empty tin.
3 marks
Evidence that the number of screws (n) in one box must satisfy either
95 ≤ n ≤ 104 or 95 ≤ n < 105 (2 marks)
Final inequality written as
950 ≤ n ≤ 1040 or 950 ≤ n < 1041 (1 mark)
Final inequality cannot be 950 ≤ n < 1050 as this implies n could be more than 1040 which is not possible.
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