What is1-100 added up?

The sum of the integers from 1 to 100 can be calculated using the formula for the sum of an arithmetic series: ( S = \frac{n(n + 1)}{2} ), where ( n ) is the highest number in the series. In this case, ( n = 100 ). Plugging in the values, ( S = \frac{100(100 + 1)}{2} = \frac{100 \times 101}{2} = 5050 ). Thus, the sum of the numbers from 1 to 100 is 5050.