计算:
(1) $(-16)÷\frac{4}{3}×\frac{3}{4}÷(-2)$;
(2) $(-\frac{2}{3})×\frac{1}{2}÷\frac{1}{3}÷(-0.5)$;
(3) $(-28)÷(-6+4)+(-1)×5$;
(4) $(-\frac{5}{7})×\frac{1}{2}+(-\frac{1}{2})÷1\frac{2}{5}$;
(5) $\frac{10}{3}+(\frac{3}{10}-\frac{8}{15})÷(-\frac{7}{20})$;
(6) $999\frac{8}{9}÷(-1\frac{1}{9})+(-\frac{3}{2})×(-\frac{3}{5})$;
(7) $4.12×(-\frac{7}{3})+6.88÷(-\frac{3}{7})-\frac{7}{5}×(-\frac{3}{7})$;
(8) $12÷(\frac{1}{6}-\frac{1}{2})+2×\frac{1}{4}-\left|\frac{1}{2}-3\right|$;
(9) $(1-\frac{1}{100})×(1-\frac{1}{99})×(1-\frac{1}{98})×···×(1-\frac{1}{3})×(1-\frac{1}{2})$。
(1) $(-16)÷\frac{4}{3}×\frac{3}{4}÷(-2)$;
(2) $(-\frac{2}{3})×\frac{1}{2}÷\frac{1}{3}÷(-0.5)$;
(3) $(-28)÷(-6+4)+(-1)×5$;
(4) $(-\frac{5}{7})×\frac{1}{2}+(-\frac{1}{2})÷1\frac{2}{5}$;
(5) $\frac{10}{3}+(\frac{3}{10}-\frac{8}{15})÷(-\frac{7}{20})$;
(6) $999\frac{8}{9}÷(-1\frac{1}{9})+(-\frac{3}{2})×(-\frac{3}{5})$;
(7) $4.12×(-\frac{7}{3})+6.88÷(-\frac{3}{7})-\frac{7}{5}×(-\frac{3}{7})$;
(8) $12÷(\frac{1}{6}-\frac{1}{2})+2×\frac{1}{4}-\left|\frac{1}{2}-3\right|$;
(9) $(1-\frac{1}{100})×(1-\frac{1}{99})×(1-\frac{1}{98})×···×(1-\frac{1}{3})×(1-\frac{1}{2})$。
答案
(1)$\frac{9}{2}$
【错因分析】对仅含有乘除的式子,如果没有括号,要按照运算顺序从左到右依次运算,不可在计算的时候先算$\frac{4}{3}×\frac{3}{4}$.
(2)2 (3)9 (4)$-\frac{5}{7}$ (5)4
(6)原式=$(1\ 000-\dfrac{1}{9})×(-\dfrac{9}{10})+\dfrac{9}{10}=-899$.
(7)$-25\dfrac{1}{15}$ (8)$-38$
(9)原式=$\dfrac{99}{100}×\dfrac{98}{99}×\dfrac{97}{98}×···×\dfrac{2}{3}×\dfrac{1}{2}=\dfrac{1}{100}$.
【错因分析】对仅含有乘除的式子,如果没有括号,要按照运算顺序从左到右依次运算,不可在计算的时候先算$\frac{4}{3}×\frac{3}{4}$.
(2)2 (3)9 (4)$-\frac{5}{7}$ (5)4
(6)原式=$(1\ 000-\dfrac{1}{9})×(-\dfrac{9}{10})+\dfrac{9}{10}=-899$.
(7)$-25\dfrac{1}{15}$ (8)$-38$
(9)原式=$\dfrac{99}{100}×\dfrac{98}{99}×\dfrac{97}{98}×···×\dfrac{2}{3}×\dfrac{1}{2}=\dfrac{1}{100}$.
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