How to locate a specific slide with the help of a given layout in Google Slides?

I have a presentation of 38 slides. Looking at the main theme, I see that a slide uses a specific "Large Number" presentation. But I do not see any slides using this layout. I went through all the slides and made sure that each of them used the right layout. How can I locate this seemingly "ghost" slide so that I can delete or modify it to use the correct layout?