（1）5.01-1.9+4.99 =5.01+4.99-1.9 =10-1.9=8.1 （2）12.7+12.5÷0.5=12.7+25=37.7（3）0.65×6.4-0.65×5.4 =0.65×（6.4-5.4 ）=0.65×1=0.65（4）96÷（15.4-12.2）=96÷3.2=30
