Count values from field i have a content-type "participants" with a field "number".

i want to calculate the total of all the values that are inserted in all the "participants"-node.

ie:

Node 1 -> 200 participants
Node 2 -> 3 participants
Node 3 -> 15 participants 

Total: 218

Only the result should be visible

I was thinking to do it with views, but i'm not succeeding.

Any suggestions?
Use views calc to achieve this behaviour, This module adds simple calculations to a views table: https://www.drupal.org/project/views_calc