2. 计算:
(1) $(-3\dfrac{1}{3}) + 2.19 + 5\dfrac{3}{8} + (-4\dfrac{3}{4}) + 7.81 + (-4\dfrac{2}{3})$；
(2) $(\dfrac{5}{12} - \dfrac{7}{9} - \dfrac{2}{3}) ÷ (-\dfrac{1}{36})$；
(3) $(\dfrac{1}{4} - \dfrac{2}{9} + 3\dfrac{1}{12} - \dfrac{1}{18}) ÷ (-\dfrac{1}{36}) - 23 × 87.6 - 23 × 12.4$；
(4) $\dfrac{1}{1 × 3} + \dfrac{1}{3 × 5} + \dfrac{1}{5 × 7} + \dots + \dfrac{1}{99 × 101}$；
(5) $1 - \dfrac{1}{2} - \dfrac{1}{6} - \dfrac{1}{12} - \dots - \dfrac{1}{9900}$；
(6) $(\dfrac{9}{20} - \dfrac{11}{30} + \dfrac{13}{42} - \dfrac{15}{56} + \dfrac{17}{72}) × \dfrac{121212}{131313}$；

(1)$2\dfrac{5}{8}$ (2)$37$ (3)$-2410$ (4)$\dfrac{50}{101}$ (5)$\dfrac{1}{100}$ (6)$\dfrac{1}{3}$