四年级小数简便运算及答案.ppt

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,=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,=19.826(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,=23.1210.12+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 =170.9 =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(1408) 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 =10.25 =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(3.622.37),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) =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(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,(8.4+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 =(64.5+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.