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) 习题一解答 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
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