85-46+26 =85-（46-26）=85-20=65
(13+18)*6 =（11+20）*6=11*6+20*6=66+120=186
65*5*2 =65*（5*2）=65*10=650
249+402 =250-1+400+2=650+1=651
15*23*4 =15*4*23=60*（20+3）=60*20+60*3=1200+180=1380
36*25 =（40-4）*25=40*25-4*25=1000-100=900
25*125*32 =（25*4）*（8*125）=100*1000=100000
35*22 =35*（20+2）=700+70=770
5*(63*2）=63*（5*2）=63*10=630