可以简便的简便计算；99.9*7+11.1*27 0.5/0.25+0.95/0.25 4.25/2.5*（10-0.1）+0.17

99.9*7+11.1*27
=99.9*7+99.9*3
=99.9*（7+3）
=999
0.5/0.25+0.95/0.25
=（0.5+0.95）/0.25
=5.8
4.25/2.5*（10-0.1）+0.17
=1.7*9.9+0.17
=0.17*99+0.17
=0.17*(99+1)
=17

可以简便的简便计算；
99.9*7+11.1*27
解，得：
==33.3*27+11.1*27
==(33.3+11.1)*27
==44.4*27
==1198.8
0.5/0.25+0.95/0.25
解，得：
==（0.5+0.95）*1/0.25
==（0.5+0.95）*4
==2+3.8
==5.8
4.25/2.5*（10-0.1）+0.17
解，得：
==1.7*10-0.1*1.7+0.17
==17-0.17+0.17
==17

99.9*7 + 11.1*27
= 99.9*7 + 11.1*9*3
= 99.9*(7+3)
= 99.9*10
= 999
0.5/0.25 + 0.95/0.25
= (0.5 + 0.95) / 0.25
= 1.45 / 0.25
= (1.45*4) / (0.25*4)
= 5.8 / 1
= 5.8
4.25/2.5 * (10-0.1) + 0.17
= (4.25*4)/(2.5*4) * (10-0.1) + 0.17
= 17/10 * (10-0.1) + 0.17
= 17/10 * 10 - 17/10 * 0.1 + 0.17
= 17 - 0.17 + 0.17
= 17

99.9*7+11.1*27
=99.9*7+99.9*3
=99.9*（7+3）
=99.9*10
=999

0.5/0.25+0.95/0.25
=（0.5+0.95）/0.25
=1.45/0.25
=5.8

4.25/2.5*（10-0.1）+0.17
=4.25/2.5*10-4.25/2.5*0.1+0.17
=1.7*10-1.7*0.1+0.17
=17-0.17+0.17
=17

99.9*7+11.1*27
=11.1×9×7+11.1×27
=11.1×（63+27）
=11.1×90
=999
0.5/0.25+0.95/0.25
=2+3.8
=5.8
4.25/2.5*（10-0.1）+0.17
=1.7×9.9+0.17
=0.17×99+0.17
=0.17×（99+1）
=0.17×100
=17