1.计算 4.75-9.64+8.25-1.36=_____.
2.计算 3.17-2.74+4.7+5.29-0.26+6.3=_____.
3.计算 (5.25+0.125+5.75) 8=_____.
4.计算 34.5 8.23-34.5+2.77 34.5=_____.
5.计算 6.25 0.16+264 0.0625+5.2 6.25+0.625 20=_____.
6.计算 0.035 935+0.035+3 0.035+0.07 61 0.5=_____.
7.计算 19.98 37-199.8 1.9+1998 0.82=_____.
8.计算 13.5 9.9+6.5 10.1=_____.
9.计算 0.125 0.25 0.5 64=_____.
10.计算 11.8 43-860 0.09=_____.
11.计算 32.14+64.28 0.5378 0.25+0.5378 64.28 0.75-8 64.28 0.125 0.5378.
12.计算 0.888 125 73+999 3.
13.计算 1998+199.8+19.98+1.998.
14.下面有两个小数:
a=0.00…0125 b=0.00…08
1996个0 2000个0
试求a+b,a-b,a b,a b.
1+0.99-0.98-0.97+0.96+0.95-0.94-0.93+…+0.04+0.03-0.02-0.01
习题一
一、直接写出计算结果:
① 1000-547
② 100000-85426
③ 11111111110000000000-1111111111
④ 78053000000-78053
二、用简便方法求和:
①536+(541+464)+459
② 588+264+148
③ 8996+3458+7546
④567+558+562+555+563
三、用简便方法求差:
① 1870-280-520
② 4995-(995-480)
③ 4250-294+94
④ 1272-995
四、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
五、巧算下列各题:
① 996+599-402
② 7443+2485+567+245
③ 2000-1347-253+1593
④3675-(11+13+15+17+19)
一、直接写出计算结果:
① 1000-547=453
② 100000-85426=14574
③ 11111111110000000000-1111111111
=11111111108888888889
④ 78053000000-78053=78052921947
此题主要是练习直接写出“补数”的方法:从最高位写起,其各位数字用“凑九”而得,最后个位凑10而得.
二、用简便方法求和:
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
三、用简便方法求差:
① 1870-280-520
=1870-(280+520)
=1870-800
=1070
②4995-(995-480)
=4995-995+480
=4000+480=4480
③ 4250-294+94
=4250-(294-94)
=4250-200=4050
④ 1272-995
=1272-1000+5
=277
四、用简便方法计算加减混合运算:
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
③537-(543-163)-57
=537-543+163-57
=(537+163)-(543+57)
=700-600
=100
④ 947+(372-447)-572
=947+372-447-572
=(947-447)-(572-372)
=500-200
=300
五、巧算下列各题:
①996+599-402=1193
②7443+2485+567+245=10740
③2000-1347-253+1593=1993
④3675-(11+13+15+17+19)=3600