使用简便算法计算398+274 659-202 1.01*45 用脱式计算 要简便
问题描述:
使用简便算法计算
398+274 659-202 1.01*45
用脱式计算 要简便
答
398+274
=400-2+274
=400+274-2
=674-2
=672
659-202
=659-(200+2)
=659-200-2
=459-2
=457
1.01×45
=(1+0.01)×45
=1×45+0.01×45
=45+0.45
=45.45
答
398+274
=400-2+274
=400+272
=672
659-202
=659-(200+2)
=659-200-2
=459-2
=457
1.01*45
=(1+0.01)*45
=1*45+0.01*45
=45+0.45
=45.45