2＝2＝1×2 2+4＝6＝2×3 2+4+6＝12=4×5 2+4+6+8=20=4×5 . 1. We can guess what is the sum of continuous even numbers from 2 to n (n is a natural number)? 2. When n = 10, what is the sum of continuous even numbers from 2 to the tenth?

2＝2＝1×2 2+4＝6＝2×3 2+4+6＝12=4×5 2+4+6+8=20=4×5 . 1. We can guess what is the sum of continuous even numbers from 2 to n (n is a natural number)? 2. When n = 10, what is the sum of continuous even numbers from 2 to the tenth?

1.n*(n+1)
There is not an arithmetic sequence formula, which is: (first term + last term) * number of terms / 2
If you take it in, it's (2 + 2n) * n / 2 = n * (n + 1)
Or directly, when n = 1, it's 1 * 2, when n = 2, it's 2 * 3, when n = 3, it's 3 * 4
It's obviously n * (n + 1)
two point one one zero
Take ten into n * (n + 1)
10*11=110