Sum of all columns that match criteria of another column along the same row

Hi,

I would like to get the sums of all columns in B, that match criteria from column A, and then show that number. Column A is a date in the form of MM/DD. Column B is a numerical value ranging from 1-3.

So basically Sum of all Column B where the corresponding A value is the criteria e.g. 11/8

Thanks for the help I'm still somewhat new to excel and this forum has been a great benefit.