Please see the attachment. This is for a third-grader who is using straight UEB for math. I'm not sure if I should use a tactile arrow where these are shown in print or if an established braille symbol would be appropriate. Thank you for your guidance.
It seems that the sole purpose of the arrows in your examples is to guide the reader to a related piece of information on the page. In that case, we should simply indicate the relationship between items by putting them close together or, possibly, by explaining the relationship in a transcriber's note.
For example, each of the numbers (e.g., 500) in the series of totals below the separation line in your second example could have its related addition expression transcribed on the same braille line after a space (see attached picture).
Similarly, the relationship between the two presentations of 476 + 148 (one with place values written out) could be transcribed one after the other and the relationship would be clear. If you feel it is necessary, a transcriber's note could be used (e.g., "The problem is modeled first with only numbers and then with numbers and words.").