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1、一、用简便方法计算下面各题：,48.7+5.6+11.3 43.21+98.76+56.79+1.24 5.48+3.99,6.3+15.4+0.09+3.7+14.6 56.8+22.8 34.650.990.97,34.52.98 45.710.4 57.327.8,=48.7+11.3+5.6=60+5.6=65.6,=(43.21+56.79)+(98.76+1.24)=100+100=200,=5.48+(40.01)=5.48+40.01=9.47,=(6.3+3.7)+(14.6+15.4)+0.09 =40+0.09=40.09,=56.8+230.2=79.80.2=79.6
2、,=34.6511+(0.01+0.03)=32.65+0.04=32.69,=34.53+0.02=31.5+0.02=31.52,=45.7100.4=35.70.4=35.3,=57.328+0.2=29.3+0.2=29.5,67.687.32.7 3.651.280.371.77,19.8261.1735.2483.405 130.835.9+5.9,23.97+0.9+6.8 23.9+6.783.9 31.6121.271.61,=67.68(7.3+2.7) =67.6810=57.68,=3.65(1.28+0.37) 1.77 =3.651.65 1.77 =0.23,=1
3、9.826(1.173+5.248+3.405 )=19.8269.826 =10,=130. 8(35.95.9) =130.830=100.8,=23.97+1+ 70.3=31.970.3=31.67,=23.93.9+6.78 =20+6.78=26.78,=31.611.61 21.27=3021.27=8.73,27.64(5.79+1.64) 23.12(10.123.67),20.65(17.11.35) 32.75+(15.2510.68),30.1623.28+15.28 0.254.784 0.982.5,=27.641.64 5.79=265.79=20.21,=23.
4、1210.12+3.67=13+3.67=16.67,=20.65+1.3517.1=2217.1=4.9,=32.75+15.2510.68=4810.68=37.32,=30. 16(23.2815.28) =30.168=22.16,=0.2544.78=14.78=4.78,= (10.02) 2.5=12.50.022.5=2.50.05=2.45,4.520.45+5.480.45 423.9 1.499+1.4,0.2573.6 1.25131.6 10.20.41,2.512.532 4267+4.2330 8.37168,=0.257(40.9）=0.25470.9=170.
5、9=6.3,=1.2513(80.2）=1.258130.2=10130.2=26,= (10+0.2）0.41=100.41+0.20.41=4.1+0.082=4.182,=(4.52+5.48）0.45=100.45=4.5,= 42(40.1）=424420.1=1684.2=163.8,=1.4(99+1）=1.4100=140,=2.512.5(84）=(2.54)(12.58)=10100=1000,=4267+4233=42(67+33）=42100=4200,=8.37(168）=8.372=16.74,28.70.35 3102.54 11.2 9.62.4,560(140
6、8) 5.674 910.125,2.384.1+5.82.38+0.238 28.71.628.7,=28.7(0.70.5）=28.70.70.5=410.5=82,=310(2.54）=31010=31,=11.2(9.62.4）=11.24=2.8,=5601408=48=32,=5.647=1.47=9.8,=(918)(0.1258）=7281=728,=2.384.1+5.82.38+2.380.1=2.38 (4.1+5.8+0.1）=2.3810=23.8,= 28.728.71.6=11.6=1.6,110.25100.25 (80+5.6)8,=(11 10)0.25=1
7、0.25 =4,=808+5.68=10+0.7 =10.7,7.8(1.0010.26)0.26 3.5+17.899+14.3,1009.50.98+9.52 2811.11+99.998,=7.81.001(0.260.26) =7.81.001=7.8078,=(3.5+14.3)+17.899=17.8(1+99）=17.8100=1780,=1000.989.5+9.52=9.5(98+2）=9.5100=950,=2811.11+11.1198=2811.11+11.11(98)=11.11(28+72）=11.11100=1111,7.618+2.32.4 1.628(3.62
8、2.37),0.387.6+0.382.5+0.382 362.54+1.849.2,1994+199.4+19.94+1.994,=1.6281.25=1.62(81.25）=1.6210=0.162,=0.387.6+0.380.4+0.382=0.38(7.6+0.4+2)=0.3810=3.8,=1.8202.54+1.849.2=1.8(202.54)+1.849.2=1.8(50.8+49.2)=1.8100=180,=2000+200+20+260.60.060.006=22226.666=2215.334,=0.71+(22)0.7+0.73+20.7=0.7(1+4+3+2)
9、=0.710=7,0.7+21.4+2.1+20.7,(0.37510137.5)37.5 1.11.1111.11.11.1,199919981998199819991999,49.513.50.549.5+50.513,=0.375(1011)37.5 =0.37510037.5 =37.537.5 =1,=1.11.1(111)1.1=1.1111.1=1.1(111)=11,=19991998100011998199910001=0,999999+1999,= 999(10001)+1999= 99910001999+1999=999000999+1999=1000000,=49.5(
10、13.50.5)+50.513=49.513+50.513 =(49.5+50.5)13=1300,11136+8888,=11136+11188=111(36+64)=11100,9898+979798979796 880.125,1234987612339877,98+979695+94+939291+6+543+2+1,=98989897+97979796 =98(9897)+97(9796) =981+971=197,=(80+8)0.125 =800.125+80.125=10+1=11,=12339876+19876(12339876+12331)=98761233=8643,(8
11、.4+8.4+8.4+8.4)2.5,=8.442.5 =8.4(42.5)=84,= (98+979695)+(94+939291)+(6+543)+2+1=4(982)4+2+1=424+2+1=99,0.9+0.99+0.999+0.9999 12.90.72+43.53.6,0.2688.882.684.44 1.1+1.3+1.5+9.7+9.9,117.82.34.880.23 3333333333,=(1+1+1+1)(0.1+0.01+0.001+0.0001) =40.1111=3.8889,=(12.95)(0.725)+43.53.6=64.53.6+43.53.6=(6
12、4.5+43.5)3.6=30,=(0.2682.68)(8.884.44)=0.12=0.2,=(1.1+9.9)245=5.545=247.5,=117.82.348.82.3=(117.848.8)2.3=692.3=30,0.2250.335+0.3350.775+0.7750.225,199227.5+198272.5 963.225,1.616+0.436 1472+4276,=(1982+10)27.5+198272.5=1982(27.5+72.5)+1027.5 =198200+275=198475,=96(0.8425)=9680=1.2,=0.4416+0.436=0.4(416)+0.436 =0.4(64+36)=40,=143(723)+4276=4224+4276=42(24+76)=4200,5096+574+766 399.6919980.8,654321123456654322123455,2003200220002200220032003,= 399.69199820.4 = 399.69399.64 = 399.65=1998,知识回顾Knowledge Review,
