先笔算,再用计算器验算.256×34 84×173 48×217.
5-0= 6-1= 9-1= 8-3= 9-6= 4-3=
10-6= 7-5= 9-2= 10-10= 9-9= 1-1=
4-2= 10-5= 4-3= 2-2= 2-1= 6-5=
6-3= 5-3= 6-6= 8-1= 9-1= 10-4=
8-4= 9-5= 5-5= 3-3= 7-7= 8-7=