Modes of comparing quantities
Comparing quantities If we look two quantities A and B, the following are equivalent: (1) A is greater than B (2) A > B (3) B is less than A (4) B < A. Example: “3.6 kg is greater than 900 g” is equivalent to “900 g is less than 3.6 kg” In order to tell more about the situation - to characterize the way how A is greater than B - we can use some comparing conventions. I mention here the most common four conventions. Purely additive comparison (= comparing by the difference) In this convention the extra information is given by the positive difference (D) between the quantities compared. Then the following are equivalent: (1) A is (the amount) D greater than B (2) A = B + D (3) B is (the amount) D less than A (4) B = A – D. Example: “A is 25 km greater than B.” is equivalent to “B is 25 km less than A”. This convention uses on...