S = S₁ -S₂
Suma Gauss S =[n(n+1)]:2 unde n este ultimul termen al sumei
unde S₁ = 1 + 2 + 3+ .................+ 21 + 22 + 23 +......+ 100 = [100 ×(100+1)]:2=5050
S₂ = 1 + 2 + 3 +......+ 20 =[(20× (20+1)]:2= 210
S = S₁ -S₂ = 4840
