LET’S TRY ONE
For this exercise, 10.0 ± 0.2 cm means an interval from reading minus 0.2 to reading plus 0.2. What is that interval?
9.8 to 10.2 cm
10.0 − 0.2 = 9.8 and 10.0 + 0.2 = 10.2.
Learning steps & teaching tips
Use explicitly defined uncertainty intervals to report measurements without claiming more precision than the method supports.
- Read how the uncertainty is defined in the scenario.
- Calculate the lower and upper values under that definition.
- Distinguish a measured difference from a justified claim about the underlying quantities.
Try it together
Measure a paper strip with two marked rulers. State each ruler's reading convention and compare the reported ranges without treating uncertainty as a mistake.
Use the stated meaning of ± in this exercise; overlapping intervals alone do not prove equality or a difference.