When you display the value of a number variable in a text box, Articulate Storyline automatically converts the number to scientific notation if it is exceedingly large. For example, if a learner enters 123,000,000,000,000,000,000,000 in a numeric entry field, it'll display as 1.23e+23 in any variable references you've added to the course.
Similarly, if you're using variables to perform calculations and displaying the results in a text box, they'll be converted to scientific notation if the numbers are very large.
To learn more about data-entry fields and variable references, click here. To learn about number variables, click here.