I am transcribing this 2nd grade math book using UEB Code. Would you recommend for number bond boxes that are empty like the one shown (for which the student is supposed to come up with the missing number), should I leave the box empty in my tactile graphic or should I use the braille symbol for "visible space" (dots 3-4-6)?
I would be inclined to leave the tactile box simply empty (in the number bond of item 4 in your example). Let me confer with the other UEB thinkers in the NBA committee and give you a more thorough answer as soon as I can.
The committee gives a resounding "yes" to a tactile, empty box in your number bond example. This is particularly appropriate for a 2nd grade student, for whom additional braille symbols are likely to make things harder rather than easier.