I did more investigation into
https://github.com/phetsims/make-a-ten/issues/304 and made some notes in the issue. But I was unable to address the problem -- it's not a simulation that I'm familiar with. Your best bet is to contact PhET through
https://github.com/phetsims/make-a-ten/issues/304. They have limited resource for answering 3rd-party questions. But if you add a comment with some info about your project and what you're trying to do, you're more likely to receive a response. If you don't receive a response, send an email to
phet...@colorado.edu. Sorry I couldn't address your problem.
Chris Malley
PixelZoom, Inc.