2 7/8 + (1 3/5 + 1 1/8) = 7 1 /2 - (1 3/8 + 1 1/2) = 9 1/16 - (5/8 + 7/16) = 7 3/4 + (2 7/8 - 1 3/4 ) =

1. 1 7/8 + ( 1 3/5 + 1 1/8) = 5  1/10 1) 1 3/5 +1 1/8 = 1 24/40 + 1 5/40 = 2  29/40 2) 1 7/8 +2  29/40 = 1 35/40 + 2 29/40 = 3 + 84/40 = =3+ 2 4/40 = 5  4/40 =5 1/10 2. 7 1/2 - (1 3/8+1 1/2) =4 5/8 1) 1 3/8+ 1 1/2 =1 3/8 +1 4/8 = 2 7/8 2) 7 1/2 - 2 7/8 = 7 4/8 -2  7/8 = =  60/8 - 23/8= 37/8= 4  5/8 3.  9 1/16 - (5/8+7/16)=8 1) 5/8+7/16= 10/16 +7/16 = 17/16= 1 1/16 2) 9 1/16 - 1 1/16 = 8 4. 7 3/4 + (2 7/8 - 1 3/4)= 8 7/8 1) 2 7/8 - 1 3/4 = 2 7/8 -1 6/8 = 1 1/8 2) 7 3/4 +1 1/8 = 7 6/8 + 1 1/8= 8  7/8