The sum of four continuous natural numbers is equal to 210, so what is the smallest of the four numbers?

The sum of four continuous natural numbers is equal to 210, so what is the smallest of the four numbers?

Let these four numbers be x, x + 1, x + 2 and X + 3 respectively
Then x + X + 1 + X + 2 + X + 3 = 210
That is 4x + 6 = 210
x=51
That is, the four numbers are 51, 52, 53, 54
The minimum number is 51

The sum of four continuous natural numbers is equal to 330, so what is the smallest of the four numbers?

Method 1
Let the four continuous natural numbers be n, N + 1, N + 2 and N + 3 from small to large
n+n+1+n+2+n+3=330
4n=324
n=81
The other three are 82, 83 and 84
The smallest is 81
Method 2
In addition to the minimum, the other three larger numbers are 1 + 2 + 3 = 6 more than the minimum, so there is
(330-6)÷4=324÷4=81.
The minimum number is 81

The sum of four consecutive natural numbers is 390. Find the largest one

Let the largest natural number be x, then
The four continuous natural numbers are x-3, X-2, X-1 and X-2
(X-3)+(X-2)+(X-1)+X=390
4X-6=390
4X=396
X=99
The largest natural number is 99