计算(能简便的要用简便方法计算). 368-128+32-72   2096-884-116-996   1998-(9

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  • 解题思路:(1)(2)利用交换律与减法的性质简算;

    (3)利用减法的性质简算;

    (4)把299=300-1计算;

    (5)(11)利用除法的性质简算;

    (6)(10)(12)利用乘法分配律简算;

    (7)先算乘法,再算减法,最后算加法;

    (8)先算括号里面的除法,再算减法,最后算括号外面的除法;

    (9)先算乘法和除法,再算减法.

    (1)368-128+32-72

    =368+32-(72+128)

    =400-200

    =200;

    (2)2096-884-116-996

    =2096-996-(884+116)

    =1100-1000

    =100;

    (3)1998-(998-376)

    =1998-998+376

    =1000+376

    =1376;

    (4)345+299

    =345+300-1

    =645-1

    =644;

    (5)600÷24

    =600÷6÷4

    =100÷4

    =25;

    (6)44×99

    =44×100-44×1

    =4400-44

    =4356;

    (7)3562-15×209+188

    =3562-3135+188

    =645;

    (8)3737÷(67-720÷24)

    =3737÷(67-30)

    =3737÷37

    =101;

    (9)16×28-240÷15

    =448-16

    =432;

    (10)36×102-36×2

    =36×(102-2)

    =36×100

    =3600;

    (11)1300÷25÷4

    =1300÷(25×4)

    =1300÷100

    =13;

    (12)11×78+11×23-11

    =11×(78+23-1)

    =11×100

    =1100.

    点评:

    本题考点: 整数四则混合运算.

    考点点评: 整数混合运算的关键是抓住运算顺序,正确按运算顺序计算,适当利用运算定律简算.