Assuming that the user is talking about Microsoft Word, the options available when using the replace feature include replace, replace all, and find next. First, the Find what and Replace with boxes locates a word or phrase and replaces it with the new text. Selecting the replace option will update one instance while the replace all option will update all instances without stopping at each one. You can click on the Find Next several times until you come to the instance that you want to update.
The gear ratios would look like A:B=1:9 and C:D=1:32 if you are just needing the gear teeth ratio. Not a lot of information to go off of from the question though
