1. 口算:
(1)$(-3)-(-5)=$
(3)$7.2-(-4.8)=$
(5)$-2.5-5.9=$
(7)$2-8=$
(9)$(-8)-8=$
(11)$0-(-6)=$
(13)$(-\frac {2}{5})-(-\frac {3}{5})=$
(15)$0-(-\frac {3}{4})=$
(1)$(-3)-(-5)=$
2
(2)$0-7=$-7
(3)$7.2-(-4.8)=$
12
(4)$|-1|-3=$-2
(5)$-2.5-5.9=$
-8.4
(6)$1.9-(-0.6)=$2.5
(7)$2-8=$
-6
(8)$-3-6=$-9
(9)$(-8)-8=$
-16
(10)$0-6=$-6
(11)$0-(-6)=$
6
(12)$16-47=$-31
(13)$(-\frac {2}{5})-(-\frac {3}{5})=$
$\frac{1}{5}$
(14)$\frac {1}{2}-\frac {1}{3}=$$\frac{1}{6}$
(15)$0-(-\frac {3}{4})=$
$\frac{3}{4}$
(16)$(-2)-(+\frac {2}{3})=$$-2\frac{2}{3}$
答案：(1)2 (2)-7 (3)12 (4)-2 (5)-8.4 (6)2.5 (7)-6 (8)-9 (9)-16 (10)-6 (11)6 (12)-31 (13)$\frac{1}{5}$ (14)$\frac{1}{6}$ (15)$\frac{3}{4}$ (16)$-2\frac{2}{3}$
2. 计算:
(1)$-13-|-7|;$ (2)$3\frac {1}{4}-0.75;$ (3)$3\frac {7}{12}-\frac {3}{4};$
(4)$10\frac {1}{3}-\frac {26}{5};$ (5)$(-\frac {1}{2})-(-1\frac {1}{3});$ (6)$(-2\frac {7}{10})-(-3\frac {3}{5}).$
(1)$-13-|-7|;$ (2)$3\frac {1}{4}-0.75;$ (3)$3\frac {7}{12}-\frac {3}{4};$
(4)$10\frac {1}{3}-\frac {26}{5};$ (5)$(-\frac {1}{2})-(-1\frac {1}{3});$ (6)$(-2\frac {7}{10})-(-3\frac {3}{5}).$
答案：(1)-20 (2)$\frac{5}{2}$ (3)$\frac{17}{6}$ (4)$\frac{77}{15}$ (5)$\frac{5}{6}$ (6)$\frac{9}{10}$
解析：
(1)$-13-|-7|=-13-7=-20$;
(2)$3\frac{1}{4}-0.75=\frac{13}{4}-\frac{3}{4}=\frac{10}{4}=\frac{5}{2}$;
(3)$3\frac{7}{12}-\frac{3}{4}=\frac{43}{12}-\frac{9}{12}=\frac{34}{12}=\frac{17}{6}$;
(4)$10\frac{1}{3}-\frac{26}{5}=\frac{31}{3}-\frac{26}{5}=\frac{155}{15}-\frac{78}{15}=\frac{77}{15}$;
(5)$(-\frac{1}{2})-(-1\frac{1}{3})=-\frac{1}{2}+\frac{4}{3}=-\frac{3}{6}+\frac{8}{6}=\frac{5}{6}$;
(6)$(-2\frac{7}{10})-(-3\frac{3}{5})=-\frac{27}{10}+\frac{18}{5}=-\frac{27}{10}+\frac{36}{10}=\frac{9}{10}$.
(2)$3\frac{1}{4}-0.75=\frac{13}{4}-\frac{3}{4}=\frac{10}{4}=\frac{5}{2}$;
(3)$3\frac{7}{12}-\frac{3}{4}=\frac{43}{12}-\frac{9}{12}=\frac{34}{12}=\frac{17}{6}$;
(4)$10\frac{1}{3}-\frac{26}{5}=\frac{31}{3}-\frac{26}{5}=\frac{155}{15}-\frac{78}{15}=\frac{77}{15}$;
(5)$(-\frac{1}{2})-(-1\frac{1}{3})=-\frac{1}{2}+\frac{4}{3}=-\frac{3}{6}+\frac{8}{6}=\frac{5}{6}$;
(6)$(-2\frac{7}{10})-(-3\frac{3}{5})=-\frac{27}{10}+\frac{18}{5}=-\frac{27}{10}+\frac{36}{10}=\frac{9}{10}$.