小學(xué)五年級數(shù)學(xué)計(jì)算能力競賽試題(附答案)

小學(xué)五年級數(shù)學(xué)計(jì)算能力競賽試題（時間：60分鐘，總分100分）一、口算（每題0.5分，共20分）0.8×0.5=0.4，1.25×4=5，3×3=9，24÷30=0.83.7-2.5=1.2，2.2×0.6=1.32，0.75+0.25=1，17÷100=0.172.8×4=11.2，0.15÷0.3=0.5，20-0.2=19.8，2.5×0.4=15.5+55=60，55.6÷0.2=278，1003÷0.01=100300，3.5×0.6=2.110.8÷9=1.2，0.95-0.36=0.59，0.13×4=0.52，84÷4.2=202.26-0.6=1.66，0.63+0.47=1.1，0.87÷0.3=2.9，100÷12.5=85.2×4=20.8，0.25×40=10，169÷1.3=130，6.5+0.35=6.851.44÷1.2=1.2，20-14.2=5.8，3.5×0.4=1.4，2.5×2.4=69.1÷7=1.3，0.72÷0.6=1.2，2.3×0.6=1.38，11-1.1=9.99÷2.5÷4=0.9，4.5×6×0.2=5.4二、計(jì)算下面各題。（每題2分，共30分）15.4+5.6÷7=16.2，12.3×3.1-25.9=38.13-25.9=12.23，(16.7-1.4)÷3=15.3÷3=5.12.3-1.5+4.5×4=0.8+18=18.8，5.6÷0.8-1.9×3=7-5.7=1.3，18-(0.6+2.4×5)=18-12.6=5.45.4(0.24÷0.3+5)×1.5,(5-0.68)÷1.2+0.8(80-9.8)×0.6-2.21,(12.5-3.6×2.5)÷2,[18.95-(8.43+3.87)]×2.8,and(41-37.4)×(0.9+6.2)1.7×[34.8÷(4.3+1.7)]aregivenexpressionsthatneedtobesimplifiedusingtheappropriatemethods.Forthefirstexpression,wecansimplifyitstepbystepasfollows:5.4(0.24÷0.3+5)×1.5=5.4(0.8+5)×1.5=42.12×1.5=63.18Thesecondexpressioncanbesimplifiedasfollows:(5-0.68)÷1.2+0.8(80-9.8)×0.6-2.21=4.32÷1.2+0.8(70.2)-2.21=3.6+56.16-2.21=57.55Forthethirdexpression,wecansimplifyitasfollows:(12.5-3.6×2.5)÷2=(12.5-9)÷2=1.75Thefourthexpressioncanbesimplifiedasfollows:[18.95-(8.43+3.87)]×2.8=[18.95-12.3]×2.8=18.07Finally,thefifthexpressioncanbesimplifiedasfollows:(41-37.4)×(0.9+6.2)1.7×[34.8÷(4.3+1.7)]=3.6×7.1×1.7×[34.8÷6]=25.56Forthelastgivenexpression,wecansimplifyitasfollows:1.25÷[(12-9.5)×0.2]=1.25÷[2.5×0.2]=2.5Andforthesecondexpression,wecansimplifyitasfollows:(1.9-1.9×0.9)÷(3.8-2.8)=0.19÷1=0.19Therefore,thesimplifiedexpressionsare63.18,57.55,1.75,18.07,25.56,2.5,and0.19.2.65+8.63+7.35+11.37=30.008.5-0.26-1.74=6.501.8×10.1=(2.65+7.35)+(8.63+11.37)=20.00=8.5-(0.26+1.74)=1.8×(10+0.1)=18.183.34+6.17-1.34+3.83=12.001.25×3.2×2.5=10.00=3.34-1.34+(6.17+3.83)=(1.25×8)×(0.4×2.5)=930÷(0.6×5)=12.00=10×1=10=31000.875×101-0.875=87.5023.4-0.8-13.4-7.2=18.001.25×88=0.875×(101-1)=23.4-13.4-(0.8+7.2)=1.25×8×11=100=10+8=10×11=110=87.5018.74×0.18+1.26×0.18=3.601.9×2.3+1.9×2.7-1.9=7.60=(18.74+1.26)×0.18=1.9×(2.3+2.7-1)=20×0.18=1.9×4=3.6=7.6=21四、解決下列問題（20分）1.在空格填上合適的數(shù)字。（每題3分，共6分）a)0.5×0.25=0.125b)3.2÷0.4=82.在空格內(nèi)填上適當(dāng)?shù)臄?shù)，使等式成立。（3分）73.06－[10×(4.465+5.535)+42.06]=32.83.計(jì)算下列兩題。（每題4分，共8分）a)1＋0.99－0.98－0.97＋0.96＋0.95－0.94－0.93＋…＋0.04＋0.03－0.02－0.01=(1-0.98)+(0.99-0.97)+(0.96-0.94)+(0.95-0.93)+……(0.04-0.02)+(0.03-0.01)=0.02×50=1b)（1＋0.12＋0.23）×（0.12＋0.23＋0.34）－（1＋0.12＋0.23＋0.34）×（0.12＋0.23）設(shè)1+0.12+0.23=A，0.12+0.23=B原式=A×(B+0.34)-(A+0.3