a : 7 = 5 rest 0
a = 5 × 7 + 0
a = 35 + 0
a = 35
b : 7 = 5 rest 1
b = 5 × 7 + 1
b = 35 + 1
b = 36
c : 7 = 5 rest 2
c = 5 × 7 + 2
c = 35 + 2
c = 37
d : 7 = 5 rest 3
d = 5 × 7 + 3
d = 35 + 3
d = 38
e : 7 = 5 rest 4
e = 5 × 7 + 4
e = 35 + 4
e = 39
f : 7 = 5 rest 5
f = 5 × 7 + 5
f = 35 + 5
f = 40
g : 7 = 5 rest 6
g = 5 × 7 + 6
g = 35 + 6
g = 41
35 + 36 + 37 + 38 + 39 + 40 + 41 =
71 + 37 + 38 + 39 + 40 + 41 =
108 + 38 + 39 + 40 + 41 =
146 + 39 + 40 + 41 =
185 + 40 + 41 =
225 + 41 = 266 => suma numerelor