Problem 1

Create a function that takes a number as an argument. Add up all the numbers from 1 to the number you passed to the function. For example, if the input is 4 then your function should return 10 because 1 + 2 + 3 + 4 = 10.

addUp(4) // 10

addUp(13) // 91

addUp(600) // 180300