I might round 126.12 UP to 130 and 2.2 DOWN to 2, then multiply 130 x 2 to get 260. This UNDER-estimates the true answer, 277.4, because rounding 126.12 up to 130 is only a slight increase percentage-wise (about 3%) whereas rounding 2.2 down to 2 is a greater decrease percentage-wise (10%).
