小学四年级数学题 简便运算
来源:百度知道 编辑:UC知道 时间:2024/06/07 19:05:47
986×89-987×88 需过程
986×89-987×88
=986×89-986×88 -88
=986×(89-88)-88
=986-88
=986-100+12
=898
986×89-987×88
=986×(88+1)-(986+1)×88
=986×88+986-986×88-88
=986-88
=986-86-2
=900-2
=898
=986×88+986-987×88
=(986-987)×88+986
=-88+986
=898
89*(986-987)+987=898
=986×88+986-986×88-88
=986-88
=898 (我是3年级的尖子)
986×89-987×88
=986×(88+1)-(986+1)×88
=986X88+986-986X88-88
=986-88
=898