《2025年启东中学作业本七年级数学上册苏科版宿迁专版》

1. 口算:
(1)$(-3)+(-9)= $-12; (2)$(-4)+(-6)= $-10;
(3)$(-4)+6= $2; (4)$(-4)+14= $10;
(5)$(-14)+4= $-10; (6)$6+(-6)= $0;
(7)$0+(-6)= $-6; (8)$15+(-22)= $-7;
(9)$(-13)+0= $-13; (10)$(-0.9)+1.5= $0.6;
(11)$(-10)+6= $-4; (12)$(+12)+(-4)= $8;
(13)$(-5)+(-7)= $-12; (14)$(+6)+(-9)= $-3;
(15)$(-2.6)+(+1.2)= $-1.4; (16)$(-3.2)+(+5.2)= $2;
(17)$(-0.9)+(-2.7)= $-3.6; (18)$\frac {2}{5}+(-\frac {3}{5})= $$-\frac{1}{5}$;
(19)$(-\frac {1}{3})+\frac {2}{5}= $$\frac{1}{15}$; (20)$-\frac {1}{8}+(-0.125)= $$-\frac{1}{4}$.

答案：
(1)-12
(2)-10
(3)2
(4)10
(5)-10
(6)0
(7)-6
(8)-7
(9)-13
(10)0.6
(11)-4
(12)8
(13)-12
(14)-3
(15)-1.4
(16)2
(17)-3.6
(18)$-\frac{1}{5}$
(19)$\frac{1}{15}$
(20)$-\frac{1}{4}$

2. 计算:
(1)$-12+\frac {1}{7}$; (2)$3.14+(-5.2)$; (3)$(-4.1)+(-15.61)$;
(4)$-9.2+(-1\frac {3}{5})$; (5)$\frac {3}{10}+(-\frac {2}{5})$; (6)$(-1\frac {3}{4})+3\frac {1}{3}$.

答案：
(1)$-11\frac{6}{7}$
(2)-2.06
(3)-19.71
(4)$-10\frac{4}{5}$
(5)$-\frac{1}{10}$
(6)$\frac{19}{12}$