《2025年启东中学作业本七年级数学上册苏科版宿迁专版》

计算:
(1)$(-7)+21+(-27)-5$; (2)$18+(-12)+(-21)-(-12)$;
(3)$0.35+(-0.6)+0.25-(+5.4)$; (4)$-20-(-14)-|-18|-13$;
(5)$1.125-(+3\frac {3}{4})-(+\frac {1}{8})-0.25$; (6)$+5.7+(-8.4)+(-4.2)-(-10)$;
(7)$\frac {2}{3}-(-\frac {7}{9})+1\frac {2}{9}+(-1\frac {2}{3})$; (8)$1\frac {1}{3}-1\frac {1}{5}+\frac {5}{3}-(-0.6)-(-3\frac {3}{5})$;
(9)$\frac {2}{5}-(-1\frac {1}{2})-(+2\frac {1}{4})-(-2.75)$;
(10)$|1-\frac {1}{2}|+|\frac {1}{2}-\frac {1}{3}|+|\frac {1}{3}-\frac {1}{4}|+... +|\frac {1}{99}-\frac {1}{100}|$.

答案：
(1)-18
(2)-3
(3)-5.4
(4)-37
(5)-3
(6)3.1
(7)1
(8)6
(9)$2\frac{2}{5}$
(10)$\frac{99}{100}$