『壹』 77x99一77用簡便方法
77×99-77
=77×99-77x1
=77×(99-1)
=77x98
=77×(100-2)
=77×100-77x2
=7700-154
=1546
分析:如果這個題中間是+,就比較好算了,但是中間是減號,就增加了很多難度,但是不管怎樣都用乘法分配律來做,只是多了一步。敬請採納謝謝!
『貳』 77脳55+77脳46錛77鐨勭畝渚胯$畻
77脳55+77脳46錛77
=77脳錛55+46錛1錛
=77脳100
=7700
77*23+78*77-77
=錛23+78-1錛*77
=100*77
=7700
77脳49+77+50脳77=77x(49+1+50)=77x100=7700
綆渚胯$畻錛
8.46-(3.46-0.77)
=8.46錛3.46錛0.77
=5錛0.77
=5.77錛
77脳1001-77
=77脳1001-1脳77
=77脳(1001-1)
=77脳1000
=77000
77涔83鍔77涔17=綆渚胯$畻
=77x(83+17)
=77x100
=7700
79脳8+4脳77-2脳77
=錛2+77錛墄8+錛4-2錛墄77
=2x8+77x8+2x77
=16+77x錛8+2錛
=16+77x10
=16+770
=786
璋㈣阿錛岃烽噰綰
鍘熷紡
=45x77+23x77+32x77
=(45+23+32)x77
=100x77
=7700
=54脳(89-77)+12脳46
=54脳12+12脳46
=12脳(54+46)
=12脳100
=1200
瑙g瓟錛
77/78*77=錛78-1)/78*77=(1-1/78)*77
=77-77/78=76鍙1/78