A sum or difference of numbers is more precise than the least precise measurement number used in the computations.
This statement is generally true. When performing calculations using measured quantities, the result is typically limited in precision by the least precise measurement used in the computation.
For example, consider the calculation (10.25 + 5.3) - 2.12. In this case, the addition of 10.25 and 5.3 involves numbers with two decimal places, which means the result of their sum, 15.55, should also have two decimal places. However, when this sum is subtracted by 2.12, which has only two decimal places, the least precise number limits the precision of the final result.
In other words, when performing operations with numbers, the precision of the result is ultimately determined by the least precise number involved in the calculations. As a result, the sum or difference of numbers is more precise than the least precise measurement used in the computations.