2)
2,7 + 17,3 = 20,
4)
0,45022 + (2,7 + 17,3) = 0,45022 + 20 = 20,45022,
6)
2,7 + (3,61 + 17,3) = 2,7 + 20,91 = 23,61,
5 7/10 + 7 3/10 + 9,72 + 12,28 + 2 11/100 + 14 89/100 =
= (5 7/10 + 7 3/10) + (9,72 + 12,28) + (2 11/100 + 14 89/100) =
= 12 10/10 + 22 + 16 100/100 =
= 13 + 22 + 17 =
= (13 + 17) + 22 =
= 30 + 22 = 52