To find the sum of an arithmetic series, we can use the formula:

S = (n/2)(a + l)

where S is the sum of the series, n is the number of terms, a is the first term, and l is the last term.

In this case, the first term (a) is 2, the last term (l) is 100, and the common difference (d) is 2 (since each term increases by 2).

We can find the number of terms (n) using the formula:

l = a + (n-1)d

Substituting the given values:

100 = 2 + (n-1)(2)
100 = 2 + 2n - 2
100 = 2n
n = 50

Now we can substitute the values into the sum formula:

S = (n/2)(a + l)
S = (50/2)(2 + 100)
S = 25(102)
S = 2550

Therefore, the sum of the series 2 + 4 + 6 + 8 + ... + 100 is 2550.