4,61 + (2,29) =

-3,08+1,69=

3/10 + (-4/5) =

-1/20+1/30=

5/8 + (-1) =

2 3/4 + (-9 5/6) =

4,61+2,29=6,9

- (3,08-1,69) = - 1,39

3/10-4/5 = 3/10 - 8/10 = - 5/10 = - 1/2

-1/20+1/30 = - (1/20-1/30) = - (3/60 - 2/60) = - 1/60

5/8-1 = 5/8 - 8/8 = - 3/8

2 3/4 - 9 5/6 = - (9 5/6 - 2 3/4) = - (9 10/12 - 2 9/12) = - 7 1/12