287+129 631﹣279 367+278 728﹣522 > > > .
口算.﹣= += 2﹣= +=﹣= ﹣= ++= 1﹣﹣=﹣+= 5﹣﹣=
直接写得数.7.2÷9= ﹣= += ﹣+= 5﹣= ﹣×0=
= .
直接写得数.= = = == = = =
﹣.