简便计算.①111111÷1111×3333=______②6.25×0.16+2.64×0.0625+5.2×6.25

3个回答

  • 解题思路:①调整运算顺序,原式变为111111×3333÷1111,即111111×(3333÷1111),计算即可;

    ②根据数字特点,原式变为6.25×0.16+2.64×6.25+5.2×6.25,运用乘法分配律简算;

    ③把[1/6]拆成([1/2]-[1/3]),把[1/12]拆成([1/3]-[1/4]),运用加法交换律与结合律简算.

    ①111111÷1111×3333,

    =111111×3333÷1111,

    =111111×(3333÷1111),

    =111111×3,

    =333333;

    ②6.25×0.16+264×0.0625+5.2×6.25,

    =6.25×0.16+2.64×6.25+5.2×6.25,

    =6.25×(0.16+2.64+5.2),

    =6.25×8,

    =(6+0.25)×8,

    =48+2,

    =50;

    ③[1/2]-[1/3]+[1/4]-[1/5]+[1/6]-[1/12],

    =(1-[1/2])-[1/3]+[1/4]-[1/5]+([1/2]-[1/3])-([1/3]-[1/4]),

    =1-[1/2]+[1/2]-([1/3]+[1/3]+[1/3])+([1/4]+[1/4]-[1/5]),

    =[1/4]+[1/4]-[1/5],

    =[1/2]-[1/5],

    =[3/10].

    故答案为:333333,50,[3/10].

    点评:

    本题考点: 四则混合运算中的巧算.

    考点点评: 完成此题,注意分析式中数据,灵活运用运算技巧或运算定律进行简算.