I have an Excel spreadsheet with the grades of over 100 students. The children can get either a 1-, 1, 1+, 2-, 2, 2+, 3-, 3, 3+ etc. However the conditional formatting isn't working. It's not recognizing the numbers with a - or a + as a number. Is there any way to fix this? I've had to change the number and enter it manually in a new column for the conditional formatting to work. Ideally I want the conditional formatting to acknowledge that 1- and 1+ = 1 and so if their target was a 5 they'd be >2 below target so it would turn red.

Thank you very much for any help