试题预览
基础班 1.用简便方法求和: ①536+(541+464)+459 ② 588+264+148 ③ 8996+3458+7546 ④567+558+562+555+563 解答: ① 536+(541+464)+459=(536+464)+(541+459)=2000 ② 588+264+148=588+(12+252)+148=(588+12)+(252+148)=600+400=1000 ③ 8996+3458+7546=(8996+4)+(3454+7546)=9000+11000(把 3458分成 4和=9000+11000 3454)=20000 ④ 567+558+562+555+563=560×5+(7-2+2-5+3)(以560为基准数)=2800+5=2805
2.用简便方法求差: ① 1870-280-520 ② 4995-(995-480)
③ 4250-294+94 ④ 1272-995 解答: ① 1870-280-520=1870-(280+520)=1870-800=1070 ②4995-(995-480)=4995-995+480=4000+480=4480 ③4250-294+94=4250-(294-94)=4250-200=4050 ④ 1272-995=1272-1000+5=277
3.用简便方法计算下列各题: ① 478-128+122-72 ② 464-545+99+345 ③ 537-(543-163)-57 ④ 947+(372-447)-572 解答:① 478-128+122-72=(478+122)-(128+72)=600-200=400 ② 464-545+99+345=464-(545-345)+100-1=464-200+100-1=363 ③ 537-(543-163)-57=537-543+163-57=(537+163)-(543+57)=100 ④ 947+(372-447)-572=947+372-447-572=(947-447)-(572-372)=300
提高班 1.用简便方法求和: ①536+(541+464)+459 ② 588+264+148 ③ 8996+3458+7546 ④567+558+562+555+563 解答: ① 536+(541+464)+459=(536+464)+(541+459)=2000 ② 588+264+148=588+(12+252)+148=(588+12)+(252+148)=600+400=1000 ③ 8996+3458+7546=(8996+4)+(3454+7546)=9000+11000(把 3458分成 4和=9000+11000 3454) =20000 ④ 567+558+562+555+563=560×5+(7-2+2-5+3)(以560为基准数)=2800+5=2805
2.用简便方法求差:
① 1870-280-520 ② 4995-(995-480) ③ 4250-294+94 ④ 1272-995 解答: ① 1870-280-520=1870-(280+520)=1870-800=1070 ②4995-(995-480)=4995-995+480=4000+480=4480 ③4250-294+94=4250-(294-94)=4250-200=4050 ④ 1272-995=1272-1000+5=277
3.用简便方法计算下列各题: ① 478-128+122-72 ② 464-545+99+345 ③ 537-(543-163)-57 ④ 947+(372-447)-572 解答:① 478-128+122-72=(478+122)-(128+72)=600-200=400 ② 464-545+99+345=464-(545-345)+100-1=464-200+100-1=363 ③ 537-(543-163)-57=537-543+163-57=(537+163)-(543+57)=100 ④ 947+(372-447)-572=947+372-447-572=(947-447)-(572-372)=300
精英班 1.用简便方法求和: ①536+(541+464)+459 ② 588+264+148 ③ 8996+3458+7546 ④567+558+562+555+563 解答: ① 536+(541+464)+459=(536+464)+(541+459)=2000 ② 588+264+148=588+(12+252)+148=(588+12)+(252+148)=600+400=1000 ③ 8996+3458+7546=(8996+4)+(3454+7546)=9000+11000(把 3458分成 4和=9000+11000 3454) =20000 ④ 567+558+562+555+563=560×5+(7-2+2-5+3)(以560为基准数)=2800+5=2805
2.用简便方法求差: ① 1870-280-520 ② 4995-(995-480) ③ 4250-294+94 ④ 1272-995 解答: ① 1870-280-520=1870-(280+520)=1870-800=1070 ②4995-(995-480)=4995-995+480=4000+480=4480 ③4250-294+94=4250-(294-94)=4250-200=4050 ④ 1272-995=1272-1000+5=277
3.用简便方法计算下列各题:
① 478-128+122-72 ② 464-545+99+345 ③ 537-(543-163)-57 ④ 947+(372-447)-572 解答:① 478-128+122-72=(478+122)-(128+72)=600-200=400 ② 464-545+99+345=464-(545-345)+100-1=464-200+100-1=363 ③ 537-(543-163)-57=537-543+163-57=(537+163)-(543+57)=100 ④ 947+(372-447)-572=947+372-447-572=(947-447)-(572-372)=300