Estimation & error intervals
Edexcel GCSE Maths revision on Estimation & error intervals. Aligned to the Pearson Edexcel GCSE Mathematics 1MA1 specification. This bank has 16 practice questions on this topic.
Sample questions (3 of 16)
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Question 1
What is the result of 4.1 multiplied by 8.9 estimated by rounding each number to the nearest whole number?
- A) Thirty six as four times nine
- B) Forty five as five times nine
- C) Thirty two as four times eight
- D) Twenty eight as four times seven
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Answer: Thirty six as four times nine
Rounding 4.1 gives 4, and rounding 8.9 gives 9. Multiplying these gives 36, which is a useful estimation for the actual product of 36.49.
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Question 2
A length is measured as 14 cm, rounded to the nearest centimetre. What is the lower bound of this measurement?
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Answer: 13.5
The lower bound is found by subtracting half of the degree of accuracy from the measured value. Since the measurement is to the nearest 1 cm, we subtract 0.5 cm from 14 cm to get 13.5 cm.
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Question 3
Which of these expressions provides the best estimate for the calculation 502 divided by 9.8?
- A) Five hundred divided by ten
- B) Four hundred divided by eight
- C) Six hundred divided by twelve
- D) Seven hundred divided by nine
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Answer: Five hundred divided by ten
Rounding 502 to 500 and 9.8 to 10 makes the calculation 500 divided by 10, which equals 50. This provides a much simpler mental estimate than the other options.
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13 more questions on Estimation & error intervals — plus mistakes tracking and spaced repetition across the whole Maths spec.