Prealgebra: Operations

Problem : 46 + 78 + 54 = ?

Problem : (56 + 7) + 13 = ?

Problem : 67 + 11 + 21 + 68 = ?

Problem : (52 + 85) + (5 + 3) = ?

Problem : 34 + 0 + 54 + 26 + 18 + 6 = ?

Problem : (5 + 64) + 6 = 5 + (64 + 6)

Problem : (5 + 64) + 6 = (64 + 5) + 6

Problem : 117 + 0 + 65 = 117 + 65

Problem : 54 + 2 + 7 + 1 = 1 + 2 + 7 + 54

Problem : 2 + (3 + 4) + 5 = (2 + 3) + (4 + 5)