99×0.625+0.625=(99+1)×0.625=100×0.625=62.5
99×0.625+0.625=(99+1)×0.625=100×0.625=62.5
(100-1)x0.625+0.625=100x0.625-0.625+0.625=100x0.625=62.5
(99十1)x0.625二62.5