简算过程674一398,189十292
问题描述:
简算过程674一398,189十292
答
674 - 398 = 674 - (400 - 2)= 674 - 400 + 2 = 276
189 + 292 = 189 + (300 - 8)= 189 + 300 - 8 = 481
答
674-398
=674-400+2
=274+2
=276
189+292
=189+300-8
=489-8
=481