Guidelines and Standards for Tactile Graphics states:
126.96.36.199 Label Placement Numeric and alphabetic labels for ordinary (regular) coordinates (scale marks) should be placed below the number line regardless of their placement in print.
A questions ask, "What number is represented by Point C on the number line." In print the coordinate markers are 0, 5, 10, C, 20, 25 (below the number line). Is the C considered a coordinate label (goes below the line) or a point label (goes above the line)?
Since, this is a 2nd grade book, the number line must be drawn and distinctive marker symbols would not be used. edited by crepemyrtle on 7/3/2014
Oops. I looked at this question and consulted to get an answer, then forgot to respond. I would put the C below the number line -- it is just substituting for the actual number in this case. Although I can see that the C would be easier to find if it were above the number line.