Evaluate 100.0 − 0.56 according to the addition/subtraction rule.

Question

G1 Physics · Accepted Answer

100.0 is precise to 0.1, while 0.56 is precise to 0.01. The result must be reported to 1 decimal place? However subtraction gives 99.44 and the least decimal places is 1, so the correctly rounded value is 99.4.