I would expect that the person who created your database set the type of that field as DECIMAL (3,2)
Means the maximum a decimal number having 3 digits of which 2 digits are decimal digits.
The largest number that this format can accomodate is 9.99
It's my guess that you tried to update the field to a number greater than 9.99. MySQL truncates the input value to the largest value the column can accomodate: 9.99.
Using phpMyAdmin, ALTER the STRUCTURE of that column to a size that accomodates a larger firnat number.
Example Pulldown the DECIMAL type, enter 5,2.,
Largest value this format can accomodate is 999.99