1、34.5*8.23-34.5+2.77*34.5
=34.5*(8.23+2.77-1)
=34.5*10
=345
2、0.9999*0.7+0.1111*2.7
=0.1111*9*0.7+0.1111*2.7
=0.1111*6.3+0.1111*2.7
=0.1111*(6.3+2.7)
=0.1111*10
=1.111
3、4.75-9.63+（8.25-1.37）
=4.75-9.63+8.25-1.37
=4.75+8.25-1.37-9.63
=13-11
=2
4、17.48*37-174.8*2.7
=17.48*37-17.48*27
=17.48*(37-27)
=17.48*10
=174.8
5、50/2.5+1.8*4.5
=20+9/5*9/2
=20+81/10
=20+0.81
=28.1
6、6.87*[40/(3.49-3.09)]
=6.87*[40/0.4]
=6.87*[40/(2/5)]
=6.87*40*5/2
=6.87*20*5
=6.87*100
=687