Thank you for your question, Christine!

I agree that the equal sign with a dot over it should be brailled just like the description says, using “dot over previous item.” So, your equal sign with a dot over it (in your book meaning “approximately equal to”) should be transcribed as you describe (also shown below).

“7^4

If you can, will you please share in what UEB resource you found a transcription of the equal with a dot above and below and what that transcription was?

Thank you!
–Kyle