Check boxes, variables and math
Hello. I am working on an activity in Storyline 360, where the learner can check off check boxes to add/subtract values to a total (the total is a variable). It is set up so that there are 5 pairs of check boxes, each pair is a button set (so you can only choose one box in each set). As you select a box in each pair the total is adjusted.
I was able to set it up so that when the learner toggles between the boxes in a pair it will adjust the total correctly. Yay!
However, I cannot seem to figure out how to prevent a user from checking the same box repeatedly. When that happens, the total keep getting adjusted. I would like to somehow set it so that once a box is checked it cannot be checked again. I tried setting conditions but that did not work. I also tried creating a true/false variable to control the checkbox but that approach was also unsuccessful. I am pretty sure I am overlooking something obvious.
I have attached the slide. Any ideas are most welcome.