下面各题怎样简便就怎样算. ①125×32×25 ②32.62-2.25-3.75 ③146×34+34×54④85×102 ⑤6000÷125÷8 ⑥672-36+64.
问题描述:
下面各题怎样简便就怎样算.
①125×32×25 | ②32.62-2.25-3.75 | ③146×34+34×54 |
④85×102 | ⑤6000÷125÷8 | ⑥672-36+64. |
答
①125×32×25,
=125×(8×4)×25,
=(125×8)×(4×25),
=1000×100,
=100000;
②32.62-2.25-3.75,
=32.62-(2.25+3.75),
=32.62-6,
=26.62;
③146×34+34×54,
=(146+54)×34,
=200×34,
=6800;
④85×102,
=85×(100+2),
=85×100+85×2,
=8500+170,
=8670;
⑤6000÷125÷8,
=6000÷(125×8),
=6000÷1000,
=6;
⑥672-36+64,
=636+64,
=700.
答案解析:①把32拆成8×4,再根据乘法交换律和结合律进行简算即可;
②32.62连续减去2.25与3.75,等于减去2.25与3.75的和;
③根据乘法分配律进行简算即可;
④把102拆成100+2,再根据乘法分配律进行简算即可;
⑤6000连续除以125与8,等于除以125与8的积;
⑥先计算减法,再计算加法.
考试点:整数四则混合运算;运算定律与简便运算;小数四则混合运算.
知识点:四则混合运算,一般先找清运算顺序,然后再进行计算,能简算的要简算.