Error intervals are the limits of accuracy when a number has been rounded or truncated. In other words, they represent the range of values that a number may have taken had it not been rounded off or truncated.
When a number has been truncated it has been cut off. If we truncate a number to one decimal place we delete all digits after one decimal place. If we truncate a number to two decimal places we delete all digits after two decimal places.
Example: Truncate 19.68923 to two decimal places
Solution:
In order to find the error interval of a rounded or truncated number, we follow these steps:
Case A: If rounded
Divide this place value by 2, and then add and subtract this amount to the given value to give the maximum and minimum values for your error interval.
Case B: If truncated
Add the place value to the given value. This will be the maximum value of your error interval, the given value will be your minimum.
3. Write your error interval as an inequality in the form
Minimum Value ≤ x < Maximum Value
Example: A number x has been rounded to one decimal place The result is 2.8. Write down the error interval for x.
Solution:
Example: Kasim travels 430 km, correct to the nearest 10 km. His average speed is 57.3 km/h, correct to 1 decimal place.
Calculate the shortest possible time for Jamal's journey. Give your answer correct to the nearest minute.
Solution:
The main topics in GCSE Maths are:
With regular practice of GCSE Maths topic-wise questions and GCSE Maths past pacers, you can easily score high marks.
Although many people think of GCSE maths as a difficult subject, with the correct training and preparation,you can master it in time. You can practice GCSE Maths topic-wise questions daily to improve speed, accuracy, and time and to score high marks in the GCSE Maths exam.
A grade of 4 or 5 would be considered "good" because the government has established a 4 as the passing grade; a grade of 5 is seen as a strong pass. Therefore, anything that exceeds this level would be considered good. You can practice GCSE Maths topic-wise questions to score good grades in the GCSE Maths exam.
You can get a high score in GCSE Maths through meticulous practice of GCSE Maths topic-wise questions and GCSE Maths past papers.
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