for the first term:
n= 1 there is 1 item
n=2 there are 2+1 = 3 items
n = 3 there are 3+2+1 = 3+2 = 6 items
n = 4 there are 4+3+2+1 = 4+6 = 10 items
We are adding the "n" term each time
n = 5 10+5 = 15
n= 6 15+6 = 21
n = 7 21+7 = 28
n = 8 28+8 = 36
There would be 36 items in the 8th step
