13十28十27
=13十27
=40十28
=68
28×13+18
=30×13-2×13+18
=390-26+18
=390-8
=382
(9十81十729)x0.01
=819*0.01
=8.19
3.14×52+6.28×23+6.28
=3.14×52+3.14×46+3.14×2
=3.14×(52+46+2)
=3.14×100
=314
原式
=23x130+23x70
=23x(130+70)
=23x200
=4600
或者
=230x13+230x7
=230x(13+7)
=230x20
=4600
756十198
解:简便计算
=756+198
=756+(200-2)
=756+200-2
=956-2
=954
祝学习进步。
=5×(13+41+26)
=5×80
=400