2026年初中运算计算升级卡七年级数学上册人教版第11页答案
5. 阅读下面文字:
对于$(-5\dfrac{5}{6})+(-9\dfrac{2}{3})+17\dfrac{3}{4}+(-3\dfrac{1}{2})$,可以按如下方法计算:
原式$=[(-5)+(-\dfrac{5}{6})]+[(-9)+(-\dfrac{2}{3})]+(17+\dfrac{3}{4})+[(-3)+(-\dfrac{1}{2})]$
$=[(-5)+(-9)+17+(-3)]+[(-\dfrac{5}{6})+(-\dfrac{2}{3})+\dfrac{3}{4}+(-\dfrac{1}{2})]$
$=0+(-1\dfrac{1}{4})$
$=-1\dfrac{1}{4}$.
上面这种方法叫拆项法.
仿照上面的方法,请你计算:
(1) $28\dfrac{1}{4}+(-17\dfrac{1}{2})$;
(2) $5\dfrac{1}{3}+(-4\dfrac{2}{3})+(-6\dfrac{1}{3})$;
(3) $(-3\dfrac{2}{7})+(-15.5)+(+18\dfrac{2}{7})+5\dfrac{1}{2}$;
(4) $(-2018\dfrac{5}{6})+(-2017\dfrac{2}{3})+(-1\dfrac{1}{2})+4036$.

答案

(1)$10\dfrac{3}{4}$ (2)$-5\dfrac{2}{3}$ (3)5 (4)-2