奥数简便计算1.1/100+3/100+5/100+……+95/100+97/100+99/1002.10又4/5 -(8.8—5/7)+2/73.5.2×1/4+0.18×2.5+25%4.(9.6-10又1/2÷1.25)÷(1又1/3×3分之4)5.(1+2/3)×(1-2/3)×(1+2/5)×(1-2/5)×……×(1+2/99
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奥数简便计算1.1/100+3/100+5/100+……+95/100+97/100+99/1002.10又4/5 -(8.8—5/7)+2/73.5.2×1/4+0.18×2.5+25%4.(9.6-10又1/2÷1.25)÷(1又1/3×3分之4)5.(1+2/3)×(1-2/3)×(1+2/5)×(1-2/5)×……×(1+2/99
奥数简便计算
1.1/100+3/100+5/100+……+95/100+97/100+99/100
2.10又4/5 -(8.8—5/7)+2/7
3.5.2×1/4+0.18×2.5+25%
4.(9.6-10又1/2÷1.25)÷(1又1/3×3分之4)
5.(1+2/3)×(1-2/3)×(1+2/5)×(1-2/5)×……×(1+2/99)×(1-2/99)
6.若2!=2×3,=3×4×5,=6×7×8×9×10×11,请计算:/
奥数简便计算1.1/100+3/100+5/100+……+95/100+97/100+99/1002.10又4/5 -(8.8—5/7)+2/73.5.2×1/4+0.18×2.5+25%4.(9.6-10又1/2÷1.25)÷(1又1/3×3分之4)5.(1+2/3)×(1-2/3)×(1+2/5)×(1-2/5)×……×(1+2/99
1. 1/100+3/100+5/100+……+95/100+97/100+99/100
=(1+3+……+99)/100
=[(1+99)*50/2]/100
=50/2
=25
2.10又4/5 -(8.8—5/7)+2/7
=10+4/5-(8+4/5)+(5/7+2/7)
=10+4/5-8-4/5+1
=10-8+1
=3
3.5.2×1/4+0.18×2.5+25%
=5.2×1/4+0.18×(10/4)+1/4
=(5.2+1.8+1)×1/4
=8×1/4
=2
4.(9.6-10又1/2÷1.25)÷(1又1/3×3分之4)
=[9.6-(10+1/2)×0.8]÷(4/3 × 4/3)
=(9.6-8-0.4)×9/16
=1.2×9/16
=0.675
5.(1+2/3)×(1-2/3)×(1+2/5)×(1-2/5)×……×(1+2/99)×(1-2/99)
=5/3 ×1/3 × 7/5 × 3/5 ×.×101/99 × 97/99
=1/3 × (5/3 × 3/5) × (7/5 × 5/7) ×(99/97 ×97/99) × 101/99
=1/3 ×101/99
=101/297
6. 4!/5!
=(4×5×6×7)/(5×6×7×8×9)
=1/18
1\ 1/100+3/100+5/100+……+95/100+97/100+99/100
一共50个数,组成25个100/100.所以是25.
2\ 10又4/5 -(8.8—5/7)+2/7=10又4/5 -8又4/5+(5/7+2/7)=2+1=3
3\ 5.2×0.25+1.8×2.5+1×0.25=8×0.25=2
4.(9.6-10又1...
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1\ 1/100+3/100+5/100+……+95/100+97/100+99/100
一共50个数,组成25个100/100.所以是25.
2\ 10又4/5 -(8.8—5/7)+2/7=10又4/5 -8又4/5+(5/7+2/7)=2+1=3
3\ 5.2×0.25+1.8×2.5+1×0.25=8×0.25=2
4.(9.6-10又1/2÷1.25)÷(1又1/3×4/3)=(48/5-21/2×4/5)÷16/9=(48/5-42/5)×9/16
=6/5×9/16=27/40
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