Theory
Calculate absolute uncertainty from measurement range
In a measurement, one number is never completely exact. If you only know a lower limit and an upper limit, you use the entire measurement range.
The range is the difference between the largest and smallest possible value.
You usually take the absolute uncertainty as half the range: uncertainty = (maximum - minimum) ÷ 2.
- Read the measurement rangeFind the lower limit and upper limit of the measurement range in the problem.
- Calculate the rangeWork out the intermediate step using the values from the problem.
- Take half of the rangeWork out the intermediate step using the values from the problem.
A measurement gives values between 9,8 cm and 10,4 cm. Calculate the absolute uncertainty as half the range.
- Read the measurement rangeSmallest value = 9,8. Largest value = 10,4.
- Calculate the range10,4 - 9,8 = 0,6.
- Take half of the range0,6 ÷ 2 = 0,3.