Calculate the sum of the first 20 natural numbers.
Note
Use formula n(n+1)/2 with n=20: 20×21/2 = 210, which is the sum of the first 20 natural numbers.
Calculate the sum of the first 20 natural numbers.
Use formula n(n+1)/2 with n=20: 20×21/2 = 210, which is the sum of the first 20 natural numbers.