解题思路:(1)(5)根据除法的性质简算;
(2)运用加法交换律简算;
(3)运用乘法结合律简算;
(4)根据减法的性质简算.
(1)770÷5÷77,
=770÷77÷5,
=10÷5,
=2;
(2)39+144+61,
=(39+61)+144,
=100+144,
=244;
(3)27×4×5,
=27×(4×5),
=27×20,
=540;
(4)857-318-182,
=857-(318+182),
=857-500,
=357;
(5)240÷3÷8,
=240÷(3×8),
=240÷24,
=10.
点评:
本题考点: 整数的除法及应用;整数的加法和减法;整数的乘法及应用;运算定律与简便运算.
考点点评: 此题是考查四则混合运算,要仔细观察算式的特点,灵活运用一些定律进行简便计算.