124×0.456-123×0.455
=(123+1)x0.456-123x0.455
=0.456+123x0.456-123x0.455
=0.456+123x(0.456-0.455)
=0.456+123x0.001
=0.456+0.123
=0.579
124×0.456-123×0.455
=(123+1)x0.456-123x0.455
=0.456+123x0.456-123x0.455
=0.456+123x(0.456-0.455)
=0.456+123x0.001
=0.456+0.123
=0.579