题目内容
12.计算.4$\frac{1}{6}$÷$\frac{5}{8}$-3$\frac{3}{8}$×1$\frac{1}{15}$
$\frac{6}{25}$÷9+$\frac{6}{25}$×$\frac{8}{9}$
10-[$\frac{1}{5}$-(35%-$\frac{1}{10}$)×$\frac{1}{5}$].
分析 (1)先算乘除,再算加减;
(2)先把除法化为乘法,再根据乘法分配律简便计算;
(3)先算小括号里面的减法,再算中括号里的乘法,加法,最后算中括号外的减法.
解答 解:(1)4$\frac{1}{6}$÷$\frac{5}{8}$-3$\frac{3}{8}$×1$\frac{1}{15}$
=$\frac{25}{6}×\frac{8}{5}-\frac{27}{8}×\frac{16}{15}$
=$\frac{20}{3}-\frac{18}{5}$
=$\frac{46}{15}$;
(2)$\frac{6}{25}$÷9+$\frac{6}{25}$×$\frac{8}{9}$
=$\frac{6}{25}×\frac{1}{9}+\frac{6}{25}×\frac{8}{9}$
=$\frac{6}{25}$×($\frac{1}{9}+\frac{8}{9}$)
=$\frac{6}{25}$×1
=$\frac{6}{25}$;
(3)10-[$\frac{1}{5}$-(35%-$\frac{1}{10}$)×$\frac{1}{5}$]
=10-[$\frac{1}{5}$-20%×$\frac{1}{5}$]
=10-[$\frac{1}{5}$-$\frac{1}{25}$]
=10×$\frac{4}{25}$
=$\frac{8}{5}$.
点评 考查了运算定律与简便运算,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律简便计算.
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