解题思路:①先算小括号里面的除法,再算小括号里面的加法;
②运用乘法分配律简算;
③先算小括号里面的减法,再算括号外的乘法,最后算括号外的除法;
④同时运算乘法和除法,再算加法;
⑤先把44分解成4×11,再运用乘法分配律简算;
⑥运用加法结合律简算;
⑦运用乘法结合律简算;
⑧根据连续减去两个数,等于减去这两个数的和简算.
①400-(1300÷65+35),
=400-(20+35),
=400-55,
=345;
②29+29×29,
=(1+29)×29,
=30×29,
=870;
③15×(41-17)÷30,
=15×24÷30,
=360÷30,
=12;
④19×96+962÷74,
=1824+13,
=1837;
⑤25×44,
=25×(4×11),
=25×4×11,
=100×11,
=1100;
⑥355+260+140+245,
=(355+245)+(260+140),
=600+400,
=1000;
⑦50×25×20×40,
=(50×20)×(25×40),
=1000×1000,
=1000000;
⑧645-180-245,
=645-245-180,
=400-180,
=220.
点评:
本题考点: 整数四则混合运算;运算定律与简便运算.
考点点评: 本题考查了四则混合运算,注意运算顺序和运算法则,灵活运用所学的运算定律进行简便计算.