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2、3 24 24 25 26 27 1 简便运算-2024四年级奥数精讲精练含答案#z-iJJ)jil;5(Ji,OC$J/J*).28 ffi n M fcJIJi.29#z-iJII j*1(Ji ft$J/J*)29#z-iJlj j*2(Jilt$J/J*).30#z-iJII j*3(Jilt$J/J*).31#z-iJlj j*4(Jilt$J/J*).32#z-iJlj j*5(Jilt$J/J*).33 ffi/l$i fa m.34#z-i)I I j*1(Ji ft$J/J*)3 5#z-iJlj j*2(Ji ft$J/J*)36 ffi$,t-,D!lEfaJN:!f!.
3、37#z-iJ1ljll;l(JiJ,t$J/J*).37#z-iJII j*2(Ji ft$J/J*)38 ffiJ.tfjffifaJ:!JOO.39#z-iJlj j*1(Ji ft$J/J*)39#z-iJlj j*2(Ji ft$J/J*)40#z-i)lj j*3(Ji ft$J/J*)41 ffi n$fjJ m.fa ro.42#z-i)Jj j*1(Ji ft$J/J*)42#z-iJlj j*2(Ji ft$J/J*)43 ffi+9 5-!:.44#z-M-iJ1!j*1(Ji It$J/J*)44#z-iJII j*2(Jilt$J/J*).45 ffi+-$-;JIJ
4、$fajjj.46#z-iJlj j*1(Jilt$J/J*).46#z-iJI ill;2(Ji,0C$fJ*)4 7#z-iJlj j*3(Jilt$J/J*).48#z-iJlj j*4(Ji ft$J/J*)49 m+=a f*.iaJHro&ialifdJ 50#z-i)Jj ill;1(Ji ft$W.*)50#z-iJlj j*2(Ji ft$W.*)51#z-iJII j*3(Ji ft$fJ*)52 2#z-iJlj ill;4(Jilt jJJ*)53 ffi+_$T f;E fa B,ffi I c Jcl iz,#J 54#z-iJII ill;1(Ji ft jJJ*
5、)54#z-iJlj ill;2(J ilt jJJ*).55 Jiu_-1flj jfi.;1,1-1:-3(.JB:ta=fJl,*).56/.Y/:r-J j:t:./)Z.-/)._ +m,i.I.-+C:;1 8-;I./.-5 l!-!I 1T f.:E.(aJ .,1,xz,/,JIJJ 7#z-iJlj ill;1(Ji ft jJJ*)5 7#z-iJII ill;2(Jilt jJJ*).58#z-iJII ill;3(Jilt jJJ*).59#z-iJlj ill;4(J ilt jJJ*).60#z-i)I I ill;5(Ji ft iJ*)61 ffi+E.$ff
6、 faJ tfi jJK M 62#z-iJII ill;1(Jilt iJ*)62#z-iJlj ill;2(Jilt iJ*).63#z-iJlj ill;3(Jilt iJ*).64#z-iJlj ill;4(J ilt iJ*).65#z-iJlj ill;5(Ji ft iJ*)66 ffi+/,$V3-faJ:OO 67 -iJlj ill;1(Ji J.l$iJ*)6 7#z-i;lj ill;2(Ji ft iJ*)68 ffi+-t 1l V3.,fa J m.69#z-i)lj ill;1(Ji ft iJ*)69#z-iJlj ill;2(Jilt iJ*)70#z-iJ
7、lj ill;3(Jilt iJ*)71#z-iJlj ill;4(Ji ft#_*)72 ffi+J.$,ofa:Yi.73#z-iJI ill;1(Ji,OC fJ*)73#z-iJl)iil;2(Jif.t$j!J*).74#z-iJlj ill;3(Ji ft iJ*)7 5#z-iJlj ill;4(Ji ft$fJ*)7 6#z-iJlj ill;5(Ji ft iJ*)77 ffi+A$foin faJ!:Yi 78#z-iJlj ill;1(Ji ft fJ*)7 8 3#z-i)lj fll;2(Jilt$jJJ*).79#z-iJlj fll;3(Jilt$jJJ*).80
8、#z-iJlj fll;4(Ji ft$jJJ*)81#z-iJII fll;5(Ji ft$jJJ*)82 =+.1l.1a fcJ w.83#z-i)I I fll;1(Ji ft$jJJ*)83#z-iJlj fll;2(Jilt$jJJ*).84#z-iJlj fll;3(Ji ft$jJJ*)85 ft.86 4-(20-9)+(200-8)+(2000-7)+(20000-6)+(200000-5)-(20+200+2000+20000+200000)-(9+8+7+6+5)-222220-35-222185 2+2+2+1+8+5-20 -1019 1 11J-350+(350+
9、6)+(350-2)+(350-4)+(350+2)+(350+10)-350X6+(6-2-4+2+10)2100+12-2112 2+1+1+2-6 1516-145-147-135-148-136-133,E!r1fllLV.8 sJ1JY?3.it:387+382+377+375+384+379+383,E!r1fll 121.18 sJY?1686+1683+1689+1681+1691+1685+1687+1678 1331+1341+1344+1355-1329-1337+1350,E!r1fll 121.123 sJ1Jfll5J.2 11J 2003+2002-2001-20
10、00+1999+1998-1997-1996+3+2-l 0-(2003+2002-2001-2000)+(1999+1998 1997-1996)+(3+2-1-0)-4x(200474)-2004-(86+84+82+80+78+76+74+72+2)-(79+77+75+73+71+1)(1+3+5+999+1001+1003)(2+4+6+998)(108+104+100+4)(98+94+90+2)1989+1988+1987-1986-1985-1984+1983+1982+1981-1980-1979-1978+9+8+7-6-5-4+3+2+1 3 f91J(1)25X32X6
11、3Xl25(2)25X9X64Xl25 C 1)=(A-25X(4X8)X63Xl25-(25X4)X(8Xl25)X63-lOOxlOOOx63-6300000-25x9x(4x8x2)xl25-(25x4)x(9x2)x(8xl25)-lOOxl8xlOOO-1800000-(1)25x25x25x64(2)125x7xl28x50(1)5X6X7X8X250(2)25x75x32x50(1)6x8xl2x5x50 x250(2)25X36X9+125X64X8 500 x400 x250 x8x6x5x4 4 f91J(1)720Xl7 18 C 1)=(A-720 C 2)=(A-18
12、60(2)18Xl7-40Xl7 680 (540 -18)-1860 30 1860 540Xl8-62-(1)(1)(1)1140X32 5774 1440 180Xl5 140X70 3000 125 8 75X25 98989898x9999999971010101 -(2)(2)(2)11111111 5 7200 x52 1150 600Xl2 9600Xl20 24 23Xll 40 8 f91J(1)65X499+97Xl3(2)54X99+47X301 C 1)=(A-65X(500-1)+(100-3)Xl3-65x500-65+1300-39-32500+1300-104
13、-33696-54x(l00-1)+47x(300+1)-5400-54+14100+47-10100-7-19493-(1)798x25+8lxl25(2)1007X57+994X33(1)34X403-51Xl20(2)497X22-103X36(1)402X38-33X96(2)38X999-101X76 99xll2+198x211-203x77 6 f91J(1)13Xl2-26X4+39X7(2)9966X6+6678X 18 C 1)=(A-13Xl2-13X8+13X21 13X(12-8+21)325-3322xl8+6678xl8-(3322+6678)xl8-180000
14、-(1)37X25+49X75+44Xl25(2)56X57+112X49-224Xl2(1)77777+7777+777+77(2)8+88+888+8888+88888+888888(1)8888X7+1111X44-11100(2)99X22+88X33+77X44+66X55(7777+8888)-5-(888-777)x3+(2222xl2+3333x4)-18 7 11J(1)999X999+1999(2)76543X99999+12345X99999 C 1)=(A-999X999+999+1000-999X(999+1)+1000-999000+1000-1000000-(76
15、543+12345)x99999-88888X99999-88888x(lOOOOO-l)-8888800000-88888-8888711112-(1)37x37+2x63x37+63x63(2)56X56+34X34-2X56X34(1)20092009X2008-20082008X2009(2)13361336Xl338-13381338Xl336(1)12345Xl2321-12344Xl2321+12345X42000-12344X42001(2)2008X2006+2007X2115-2006X2116-2008X2005 8 11J(1)987+798+879(2)3456+43
16、65+5643+6534(1)lzs 7J 987-900+80+7,798-700+90+8,879 800+70+9 xttt:1:_m:900+100+800-(7+8+9)xl00,80+90+70-(7+8+9)xl0,7+8+9-(7+8+9)xl 0-(7+8+9)xl00+(7+8+9)xl0+(7+8+9)(7+8+9)x(l00+10+1)24Xlll-2664(2)lzs 1g 3456-3000+400+50+6,4365-4000+300+60+5,;1t Wg IP:EJ.J t8 iJD xt,tt:E,m:3000+4000+5000+6000-(3+4+5+6
17、)x 1000,Ef 1.fr+-(3+4+5+6)xl000+(3+4+5+6)xl00+(3+4+5+6)xl0+(3+4+5+6)(3+4+5+6)x(l000+100+10+1)18Xllll 19998(1)1357+3571+5713+7135(2)2468+4682+6824+8246(1)23456+34562+45623+56234+62345(2)778899+788997+889977+899778+997788+977889 9 f91J 19971997+9971997+971997+71997+1997+997+97+7 19971997-10000000+9000
18、000+900000+70000+1000+900+90+7 9971997-9000000+900000+70000+1000+900+90+70 19971997+9971997-10000000+2x9000000+2x900000+2x70000+2xl000+2x 900+2x90+2x7 0-10000000+2x9000000+3x900000+4x70000+5xl000+6x900+7x90+8x7-10000000+18000000+2700000+280000+5000+5400+630+56-30991086-1234567+234567+34567+4567+567+
19、67+7 2334455+334455+34455+4455+455+55+5 987654+87654+7654+654+54+4 10-iJl(tf-1 1.*=(10-1)+(100-3)+(1000-2)+(10000-1)+(100000-2)=(10+100+1000+10000+100000)-(1+3+2+l+2)=111110-9=111101 1+1+1+1+0+1=5 :EFf1ifQB1iz*ZfO So 2.Jj(=(6000-5)+(5000-6)+(4000-7)+(3000-8)+(2000-9)=(6000+5000+4000+3000+2000)-(5+6+
20、7+8+9)=20000-35=19965 1+9+9+6+5=30 :EFr1ifQ1ftZfQ 300 3.)ffiA=(300-12)+(380-1)-(300-1)+(4000-1)-C 400-1)=(300+380+4000-300-400)-(l-l+l-l)-12=3968 3 X9X6X8=1296 :EFf1t5fn1iz*zfR 12960 4.ffi:t-t=(500000-5)-(40000-6)-(7000-3)-(500-9)-78=(500000-5)-(40000+7000+500+78-6-3-9)=500000-5-47560=452435 4X5X2X4
21、X3X5=2400 :EFr1ttQE1ftz1Jl 24000 s.)ffiA=C 20-1)+(200-1)+C 2000-1)+(20000-1)+(2 oo-0-1)=22 20-10=22 210 9x2+1=19 :EFr1ffQ1ft:zfQ 190-iJlltf-2 1.)ffi:i=(170+3)+(170+1)+(l 70-1)+(170-2)+(l 70+4)+(170-4)=170 x6+(3+1-l-2+4-4)=1021 1+0+2+1=4 :EFf1f5fQ*1ftzfQ 4o 2.*=1516-(140+5)-(140+7)-(140-5)-(140+8)-(1
22、40-4)-(140-7)=1516-140 x6-(5+7-5+8-4-7)=1516-840-4=672 672-;-8=84 :EFr1ifQ0 8 a 840 86 3.m(A=(380+7)+(380+2)+(380-3)+(380-5)+(380+4)+(380-1)+(380+3)=380 x7+(7+2-3-5+4-l+3)=2660+7=2667 266 7-;-18=148 3:Yr1ffu 18 sJ 3a 4.m(A=l680 x8+(6+3+9+1+11+5+7-2)=1680 x8+40=13480 13480X 16=215680 :r1ttu*16 EJf/q
23、2156800 s.lffiA=C 1340-9)+C 1340+1)+(1340+4)+(1340+15)-C 1340-11)-C 1340-3)+(1340+10)=1340X3-9+(1+4+15+11+3+10)=4020-9+44=4055 4055-;-123=32 119 :r1ffQ 123 BJjfJfQ.Ll 32 fQ 1190-UII 3 1.m(A=(86+84+82)+(80-79)+(78-77)+(76-75)+(2-1)=252+1 X40=292 2.lffiA=1+(3-2)+C 5-4)+(7-6)+(999-998)+1001+1003=1+1 X4
24、99+1001+1003=2504 ti:tEit-Bt,mlf Y.10 2 U 999 j(999-1)-;-2=499(Jl)o 3.lffiA=c 108+104)+C 100-98)+C 96-94)+C 92-90)+C 4-2)=212+2x25=262 1=.i:1-100 q:tff 5011,4i1:M1il.m-Jl,25 _g a 4.)A 1989,&61!&-iJl,1989+1988+1987-1986-1985-1984=9)4.ij-_g 61to-Er 90 1989-;-6=33130!iJ*Ur.=:1 3-.2-.1,3+2+1=6 a 125111:
25、,1-*:r-:=331 x9+6=2985 0 iJll4 1.(1)JJ(:r-:=25x25x25x(4x4x4)=(25x4)x(25x4)x(25x4)=1000000(2)J)j(A=125x7x(8X4X4)X50=(125x8)x(50X4)x(7X4)=1ooox2oox28=5600000 2.(1)1-*:x:=5x6x7x8x(2xl25)=(5x2)x(6x7)x(8xl25)=10 x42xl000=420000(2)ff(=25x25x3x(4x4x2x50)=(25x4)x(25x4)x(3x2)xS0=l00 xl00 x300=3000000 3.(1)ff
26、(:c.t=6X8Xl2X5X50X(2Xl25)=(6X5)X(8Xl25)X(50X2)Xl2=30Xl000Xl00Xl2=36000000(2)ffi:c.t=25x(4x9)x9+125x8x64=(25x4)x(9x9)+l000 x64=8100+64000=72100 4.Jffi:x:t=(500 x8)x(400 x5)x(250 x4)x6=4000 x2ooox1ooox6=48000000000 87 1.(1)M(A=(1140-=-57)x(32-=-4)=20X8=160(2)JJA=7200-=-60 x(52-=-13)=120 x4=480 2.C 1)J
27、JA=1440-=-C 180-=-15)-=-C 140-=-70)=1440-=-12-=-2=60(2)lffj=1150-=-23-=-(600-=-12)Xll=50-=-50Xll=11 3.(1)JJj=3000-=-(125X8)-=-(75-=-25)=3000-=-1000-=-3=1(2)lff(A=9600-=-(40 x8)x(120-=-24)=9600-=-320 x5=150 4.m(=98xl01010lx9xllllllll-=-1010101-=-llllllll=98X(1010101-=-1010101)X9X(llllllll-=-11111111)
28、=98X9=882-UII 6 1.(1)JffiA=(800-2)x25+(80+l)xl25=20000-50+10000+125=30000+75=30075(2)A=(l000+7)x57+(1000-6)x33=57000+399+33000-198=90000+201=90201 2.(1)A=34x(400+3)-(50+1)xl20=13600+102-6000-120=7600-18=7582(2)flf(:r.=(500-3)x22-(100+3)x36=11000-66-3600-108=11000-(66+3600+108)=7226 3.(1)Jf(j=(400+2)
29、X38-33X(100-4)=15200+76-3300+132=15200-3300+(76+132)=11900+208=12108(2)ffiA=38x(1000-1)-(100+1)x76=38000-38-7600-76=30400-(38+76)=30286 4.1*A:=(100-1)xll2+(200-2)x211-(200+3)x77=11200-112+42200-422-15400-231=(11200+42200-15400)-(112+422+231)=38000-765=37235 1.(1)Jffi:c.t=37X25+49X3X25+44X5X25=25x(37
30、+49X3+44X5)=25x404=25x400+25X4=10100(2)A=56x57+56x2x49-56x4xl2=56x(57+98-48)=56xl07=5992 2.(1)JJA=7x(11111+1111+111+11)=7xl2344=86408(2)lffiA=8x(1+11+111+1111+11111+111111)=8xl23456=987648 3.(l):r.t=1111 X8 X 7+1111 X 44-11100=llllx(56+44)-11100=111100-11100=100000(2)J=:r.t=llXllX9X2+11XllX8X3+11Xll
31、X7X4+11XllX6X5 88=11x11x(18+24+28+30)=12lxlOO=12100 4.)ffi=(7Xllll+8Xllll)-:-5-111X3+(1111x2x12+1111X3X4)-:-18=llllx(7+8)-:-5-lllx3+llllx(24+12)-:-18=llllx3-lllx3+llllx2=(1111-111)x3+2222=5222 1.(1)m(=37X37+63X37+63X37+63X63=37x(37+63)+63x(37+63)=3700+6300=10000(2)ffij=56X56-56X34+34X34-56X34=56x(56
32、-34)-34x(56-34)=56x22-34x22=(56-34)x22=484 2.(1)ffi=2OO9xlOOOlx2OO8-2OO8xlOOOlx2OO9=2OO8x2OO9xlOOO1-2OO8x2OO9xlOOO1=O(2)Jzt=l336Xl0001Xl338-1338Xl0001Xl336=1336Xl338Xl0001-1336Xl338Xl0001=0 3.(1)Jffit=1232lx(12345-12344)+(12344+1)x42OOO-12344x(42000+1)=12321+12344X42000+42000-12344X42000-12344=12321
33、+42000-12344=41977(2)ffij_=2008X(2006-2005)+(2006+1)X2115-2006X(2115+1)=2008+2006X2115+2115-2006X2115-2006=2008+2115-2006=2117 1.(1)Jzj=(1+3+5+7)xlOOO+(1+3+5+7)xlOO+(1+3+5+7)xlO+(1+3+5+7)=(1+3+5+7)X(1000+100+10+1)=16Xllll=17776(2)Jj=(2+4+6+8)xlOOO+(2+4+6+8)xlOO+(2+4+6+8)xlO+(2+4+6+8)=(2+4+6+8)x(1000
34、+100+10+1)=2ox1111=22220 2.(1)Jzt=(2+3+4+5+6)xlOOOO+(2+3+4+5+6)x 1000+(2+3+4+5+6)xlOO+(2+3+4+5+6)xlO+(2+3+4+5+6)xl=(2+3+4+5+6)x(10000+1000+100+10+1)=2ox11111=222220(2)ffiA=(7+7+8+8+9+9)xlOOOOO+(7+7+8+8+9+9)xlOOOO+(7+7+8+8+9+9)xlOOO+(7+7+8+8+9+9)xlOO+(7+7+8+8+9+9)xlO+(7+7+8+8+9+9)xl=(7+7+8+8+9+9)X(10
35、0000+10000+1000+100+10+1)=48Xllllll=5333328 1.1234567=1000000+200000+30000+4000+500+60+7,234567=200000+30000+4000+500+60+70 t?tfm Fo BJD 7f xiirtJJTI:1234567+234567=1OOOOOO+2x2OOOOO+2x3OOOO+2x4OOO+2x5OO+2x6O+2x70 r AJJo 89 A=l000000+2x200000+3x30000+4x4000+5x500+6x60+7x7=1000000+400000+90000+16000+2
36、500+360+49=1508909 2.m(=2000000+2x300000+3x30000+4x4000+5x400+6x50+7x5=2000000+600000+90000+16000+2000+300+35=2708335 3.1l=900000+2x80000+3 x7000+4x600+5x50+6x4=900000+160000+21000+2400+250+24=1083674 1083674-:-199=5445.119 1.a24=5+(24-1)X(9-5)=97 :i!-t-JU s 24 r,m 97 o 2.a29=7+(29-l)x(15-7)=231 :i!
37、-t-JUB 29 J_m 2310 3.a20=10+(20-1)x2=48(1-):J!ft0-t-fptf 481-iLo 4.a16=4+(16-1)x(8-4)=64():T-:Jt 64 fo 5.a100=10+(100-l)X4=406(1*):i!txjjWj 406 ll*o 1.n=(l0l-8)-:-(11-8)+1=32 :J!-t-ju 32 rffi o 2.n=(254-4)-:-(9-4)+1=51 /r-.*117-ill t-J=;51 Jrfi i:1 I 7,.,.-.A:!J o 3.a1=34-17=17 n=(289-1 7)-:-1 7+1=1
38、 7 :J!-t-35Uli 11 r,m o 4.n=(68-12)-:-4+1=15 :i!*-=1=51J,gT 15 3co 5.n=(30400-7540)-:-1270+1=19 19-12=1 o mtil,2016!8 A s F QS!U 30400 mio :2016!8 A sJF-fjtQSfU 30400*ELo 90 1.n=(2011-l)-:-10+1=202 1l:ci=(1+2011)X202-:-2=203212 2.1%pg n=(2013-2003)-:-1+1=11 1lA=(2003+2013)Xll-:-2-:-2008=11 3.1+2+3+4
39、+10+11+12=(1+12)Xl2-:-2=78(T):i!-t-Btitt1kA 1 stU 12 a 78 T o 4.9-10 18,8-9 17 kAlrtt-i91Ll P1-t-:JU:18,1 7,16,15,14,13,12,11,10,p(10+18)X9-:-2=126():$fli 1260 5.2+1 X(60-1)=61(*&)(1+61)X60-:-2=1860(*):lliTffilI*61*o-li 1860*o iJl(if-4 1.8 5R 2 BJWITSLi:pft1JEfJ 10,=-t-18,.=-t-26,.rrff 8;R 2 Bftjc1mfl 980 r-FB1mfI 1ru Jg rmt 8,l2SI i1:t t 1,1 if1g -t-,u,tJAJ lUffljUJJJ rm 1il B:1 to 10+18+26+980 n=(98-10)-:-8+1=12 S12=(10+98)Xl2-:-2=648 2.7 ilI 5R s;J-=1il 105,13/r kA 7:&1 .=fri:p;JB 106,:i:;e 9950 J!ir-B.=1.fzf!rjgM