6年级奥数题简便运算

2024-12-02 09:20:33
推荐回答(4个)
回答1:

2004^2-2003^2
=(2004+2003)(2004-2003)
=4007

(3又2/9+9又2/3)/(1/9+1/3)
=(29/9+29/3)/(1/9+1/3)
=29(1/9+1/3)/(1/9+1/3)
=29

2.4*(乘)20又3/5+33.1*(乘)7.6
=12/5*103/5+331/10*38/5
=12*103/25+331*19/25
=(12*103+331*19)/25
=(1200+12*3+331*20-331)/25
=7525/25
=301

(2890+5/6+7/8+7/10)/(5/6+7/8+7/10)
=2890/(5/6+7/8+7/10)+1
=2890/[(100+7*15+7*12)/120+1
=2890*120/[100+7*(15+12)]+1
=2890*120/289+1
=1200+1
=1201

回答2:

1.(2004-2003)*(2004+2003)=4007
2. (3+2/9+9+2/3)/[(3+9)/(3*9)]=(12+8/9)/(4/9)=12*9/4+2=29
3. 2.4*20.6+(20.6+12.5)*7.6
=(2.4+7.6)*20.6+12.5*7.6
=10*20.6+50*1.9=206+95=301
4.=1+2890/(5/6+7/8+7/10)=1+2890/(5*8*10+7*6*10+7*6*8)*6*8*10=1201

回答3:

1、=2004+2003=4007
2、=24
3、=301
4、=1201

回答4:

1、(2004-2003)*(2004+2003)=4007