How to "classify" a value based on a range


I have 2 tables  , one is a classification table and one is a data table 

My classification table is:

0 --- A 

2--- B

4--- C 

Which actually means that values between 0 and 2 are A ,  values between 2 and 4 are B  and values greater than 4 are C 

I also have a data table: 


Sample1  1.5 

Sample2  2.4

Sample3 4.5 


I would like to get the "classification"  for those values and get : 

Sample1 1.5  A 

Sample2 2.4 B

Sample3 4.5 C 

I have multiple of the sample data tables and all have to be classified in he same way. 

How do i do that? 

thank you