《2025年新课程课堂同步练习册七年级数学上册人教版》

1. 计算：
(1) $-1 + 4÷ \left(-\dfrac {1}{2}\right)× (-2)$；
(2) $\left(+1\dfrac {2}{7}\right)÷ \left(-\dfrac {3}{4}\right)÷ \left(-\dfrac {15}{14}\right)× \left(-\dfrac {5}{8}\right)$；
(3) $48÷ [4× (-2)-(-4)]$；
(4) $\left(-\dfrac {2}{3}\right)× \dfrac {1}{2}÷ \dfrac {1}{3}÷ (-0.5)$；
(5) $(-18)÷ 3× \dfrac {1}{3}+\left(-\dfrac {1}{6}+\dfrac {3}{8}-\dfrac {1}{12}\right)× (-48)$；
(6) $3\dfrac {1}{7}× \left(3\dfrac {1}{7}÷ 7\dfrac {1}{3}\right)× \dfrac {7}{22}÷ \left(-1\dfrac {1}{21}\right)$.

答案：
(1)15
(2)$-1$
(3)$-12$
(4)2
(5)$-8$
(6)$-\dfrac{9}{22}$

2. 已知$a$,$b$互为相反数,$c$,$d$互为倒数,$m$的倒数等于它本身,求$\dfrac {cd}{m}+(a + b)m - |m|$的值.

答案： 0或$-2$