用乘法代替减法计算下面各题
95-59= 74-47= 65-56=
用乘法代替减法计算下面各题
95-59= 74-47= 65-56=
用乘法代替减法计算下面各题
95-59=9*(9-5)=36
74-47= 9*(7-4)=27
65-56= 9*(6-5)=9
95*59
=95*(60-1)
=95*60-95
=5700-95
=5605
74*47
=(75-1)*47
=3525-47
=3478
65*56
=65*50+65*6
=3250+390
=3640
95-59=
(9-5)×9=36
74-47=
(7-4)×9=27
65-56=
(6-5)×9=9