How do I make sure event trigger only 1 time?

I created a sprite as a button and I added some actions to manipulate variables when the button is pressed (for example adding). However, it seem that it did not add just 1 time. It keep adding 1 over and over until I release the button.

Is there anyway to make sure that in a single click/press/touch, the variable will be manipulated only 1 time no matter how long it is?

Yes, under system conditions for your event, you can pick "Trigger Once" and add it to your event so it only happens once when the conditions are met.