题目内容
| ①957-420÷60 | ②38+3.4+122+6.6 | ③25×(4.41-16.4÷40) |
| ④4.8×3.27+5.73×4.8+4.8 | ⑤ | ⑥ |
解:①957-420÷60,
=957-7,
=950;
②38+3.4+122+6.6,
=(38+122)+(3.4+6.6),
=160+10,
=170;
③25×(4.41-16.4÷40),
=25×(4.41-0.41),
=25×4,
=100;
④4.8×3.27+5.73×4.8+4.8,
=4.8×(3.27+5.73+1),
=4.8×10,
=48;
⑤
,
=
×24+
×24-
×24,
=10+15-20,
=25-20,
=5;
⑥
,
=
÷[1-
],
=
,
=
.
分析:①先算除法,再算减法;
②运用加法交换了和结合律简算;
③先算小括号里面的除法,再算小括号里面的减法,最后算括号外的乘法;
④运用乘法分配律简算;
⑤运用乘法分配律简算;
⑥先算小括号里面的减法,再算中括号里面的减法,最后算括号外的除法.
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.
=957-7,
=950;
②38+3.4+122+6.6,
=(38+122)+(3.4+6.6),
=160+10,
=170;
③25×(4.41-16.4÷40),
=25×(4.41-0.41),
=25×4,
=100;
④4.8×3.27+5.73×4.8+4.8,
=4.8×(3.27+5.73+1),
=4.8×10,
=48;
⑤
=
=10+15-20,
=25-20,
=5;
⑥
=
=
=
分析:①先算除法,再算减法;
②运用加法交换了和结合律简算;
③先算小括号里面的除法,再算小括号里面的减法,最后算括号外的乘法;
④运用乘法分配律简算;
⑤运用乘法分配律简算;
⑥先算小括号里面的减法,再算中括号里面的减法,最后算括号外的除法.
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.
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