Using the operation law of rational number addition to calculate: (1) (- 0.5) + 17 of 4 + (- 19 of 2) + 9.75; (2) 1 and 3 of 4 + (- 6.5) + 3 of 4 3 of 8 + (- 1.75 + 2 and 5 of 8); (3) (- 3.5) + (- 4 of 3) + (+ 7 of 2) + 0.75 + (- 7 of 3)

Using the operation law of rational number addition to calculate: (1) (- 0.5) + 17 of 4 + (- 19 of 2) + 9.75; (2) 1 and 3 of 4 + (- 6.5) + 3 of 4 3 of 8 + (- 1.75 + 2 and 5 of 8); (3) (- 3.5) + (- 4 of 3) + (+ 7 of 2) + 0.75 + (- 7 of 3)

(1) The original formula = 3 / 8 + (- 7 / 4) + 21 / 8 = (21 / 8 + 3 / 8) + (- 7 / 4) = 5 / 4 = 1 and 1 / 4
(2) The original formula = (- 7 / 2) + (- 4 / 3) + 7 / 2 + 3 / 4 + (- 7 / 3) = 3 / 4 + (- 11 / 3) = - 35 / 12 = - 2 and 11 / 12
To convert decimal into fraction, the same denominator should be operated first, and different denominators should be operated first