1、 乘法分配律的乘法分配律的拓展与延伸拓展与延伸 3.899+3.8=3.899+3.81=3.8（99+1）=3.8100=3801357171138）（1351387117113571713871112381191198511283119119851128385119）（112111911211914948）（41)948(4194418912 912)3278116564（327648164165641482014 2.254.8+77.50.48=22.50.48+77.50.48=0.48(22.5+77.5)=0.48100=48 3.598+350.2=359.8+350.2=35
2、(9.8+0.2)=3510=350 111137+99997=111137+111197=1111(37+97)=1111100=111100 0.99990.7+0.11112.7=0.111190.7+0.11112.7=0.1111(90.7+2.7)=0.11119=0.9999 999999+1999=999999+9991+1000=999（999+1）+1000=9991000+10001=1000（999+1）=10001000=100000054211%125455.325.15.5125.125.15.3）（5.515.325.11025.15.1291175941719
3、517194171）（9594171117117113618513295131651861359213561135）（1869261135)186184183135（18131351851081585581285585185）（2518588552743394127431343）（271343404330 361.09+1.267.3=3.610.9+1.267.3=1.2310.9+1.267.3=1.2（310.9+67.3）=1.2（32.7+67.3）=1.2100=120 81.515.8+81.551.8+67.618.5=（81.515.8+81.551.8）+67.618.5=81.5（15.8+51.8）+67.618.5=81.567.6+67.618.5 =67.6（81.5+18.5）=67.6100=6760
