(1)7.29*4.6+46*2.71=7.29*4.6+4.6*27.1=4.6(7.29+27.1)
(2)2分之1÷【3分之2*(8分之1+4分之1)】=1/2/(2/3*(1/8+1/4))=1/2/(2/3*3/8)=1/2/(1/4)=2
(3)2.2*3.83+2.2*5.17+2.2=2.2*(3.83+5.17+1)=2.2*10=22
(4)6.9+4.8+3.1=6.9+3.1+4.8=14.8
(5)0.456+6.22+3.78=0.456+(6.22+3.78)=10.456
(6)15.89+(6.75-5.89)=15.89-5.89+6.75=16.75
(7)4.02+5.4+0.98=4.02+0.98+5.4=10.4
(8)5.17-1.8-3.2=5.17-(1.8+3.2)=5.17-5=0.17
(9)13.75-(3.75+6.48)=13.75-3.75-6.48=3.52
(10)3.68+7.56-2.68=3.68-2.68+7.56=8.56
(11)7.85+2.34-0.85+4.66=7.85-0.85+(2.34+4.66)=7+7=14
(12)35.6-1.8-15.6-7.2=35.6-15.6-(1.8+7.2)=20-9=11
(13)3.82+2.9+0.18+9.1=3.82+0.18+(2.9+9.1)=4+12=16
(14)9.6+4.8-3.6=9.6-3.6+4.8=10.8
(15)7.14-0.53-2.47=7.14-(0.53+2.47)=4.14