六年级奥数思维训练题及答案.txt

() : : : 200 12,10,120.(110) 1,: a= b= =a=(a-b)= 2,7:3,15,8,5:2, 7,3. 2(7+15)=5(3-8) 14+30=15-40 =70 707=490() 703=210() :490,210. 3,120,3. 120=15() (15+3)(1-)=126() 126-15=111():111. 4,75%,60,. 60-(1-75%)=240() :240. 5,.,312,6. 12(-3)=288()126-(1-)=288() :288. 6,4:3,3:2,. 4+3,3+2=35() 4:3=20:15 3:2=21:14 (2015):(2114)=50:49 :50:49. 7,22, 22(1+1)(1-)=86() :86. 8,25,6,4,110, (625-110)(6+4)=4() :4. 9,355,5,. (355-5)(1-+1)=200() 355-200=155() :200,155. 10,90,64, (90-64)(-)=42() 90-42=48():42,48. 11,100.23,32, (100+23+32)(2+3)=31 312-23=39 313-32=61 :61. 12,鹲85,. 1(1-):1(1-)=9:8 85(9+8)=5() 59=45() 58=40() :45,40. 13,.12, 1-= 12(-)=80() 80=48() 80-48=32() :48,32. 14,100,60., 1-= 1-= (100-60)(-)=72() 90-72=18() :72,18. 15,a350500,b400100.a50%,b75%,ba (350+400)-(500+100)75%-(1-75%)=300()b 300=225()b 300-225=75()b 400-225=175() 100-75=25() :b17525a. 16,ed=ad,bf=bc,od=bd,120,. sode=1. 1=15() 15(1-)=6()scdf (15-6)(1-)=7.2()sobf 120=60() 60=32.8() :32.8. 17,72/,48/. 72,48=144 14448=3() 14472=2() (1442)(2+3)=57.6(/) :57.6/. 18,5, 7,24, . 5=7(24-) =14 :14. 19,121,鹲 (1-)= 121()=165() :鹲165. 20,250,10%,25%, 250(1-10%)=225() 225(1-25%)=300() 300-250=50() :50. 21,300,55, ,(300-) 300-200=100() :200,100. 22,12,80 (130+80)(6-0.5)=20()120 360-(80-302)(6-0.5)=56156 : 120 15680. 23,38,7,8,9,3, 383-7-8-9+3=93() :93. 24,40,24,750, 1(+)=15() 750(-15)=6000() :6000. 25,125%,28, , 28(-)=180() 180=72() 180-72=108() :72,108. 26,20,30,3,16, 1-(16-3)= () 16-10=5():5. 27,40%,12, . 40%+40%+12+(40%+12)= =75() :75. 28,20%,1;100,30%,1.,. v:v=1:(1+20%)=5:6 t:t=6:5 t:1(6-5)6=6() v:v=1:(1+30%)=10:13 t 1(13-10)13= () 6-=() 1006=360() :,360. 29,2.9,11,嶨 60:(60+2)=30:31 11.5-9=2.5() 2.53031=2()=235 9+235=1135:嶨1135. 30,130, (1-)=() (1-)=() 130(+)=60() 602=120() :120. 31,6,.: () (1-):(1-)=27:28 6(28-27)=6() 627=90() 628=96() 90+96=186() () 1(1-)= 1(1-)= 6(-)=6(-)=612=72() 72+72=90+96=186() :186. 32,2,.: (1+)=“1“ 2(-)=242=84() :84. 33,8,4;48,67.: 400036008=()s 67000360048=()s (-)(48-8)3600=79600()=79.6 :79.6. () : : : 200 12,10,120.(110) 1,: 2,7:3,15,8,5:2, 3,120,3. 4,75%,60,. 5,.,312,6. 6,4:3,3:2,. 7,22, 8,25,6,4,110, 9,355,5,. 10,90,64, 11,100.23,32, 12,鹲85,. 13,.12, 14,100,60., 15,a350500,b400100.a50%,b75%,ba 16,ed=ad,bf=bc,od=bd,120,. 17,72/,48/. 18,5, 7,24, 19,121,鹲 20,250,10%,25%, 21,300,55, 22,12,80 23,38,7,8,9,3, 24,4