Do you receive data from other people and need to find data that is incorrect or does not conform? Such as text where there should be numbers? There are 2 features within Microsoft Excel that may help you.
The first is conditional formatting. You can change the format of a cell it it meets a condition, For example it you need to show all values below 50,000 then it can make them all yellow.
Another feature is validation. This can be applied to existing data then then all the cells that contain invalid data can be circled. The circles do not print, they are seen on screen only. This method is good if the data is being added to by others, the validation will help to make the new data more accurate.
Both features are useful and should be tried.