Format if cell partially matches another

Question

I have two columns with telephone numbers in them, I want cells B2 and B3 to change colour depending on whether they match the last 4 digits in the column next to them:

B2 turns green as it matches the end of A2 and B3 turns red as it does not match the last four digits of A3.

How would I go about doing this?

Answer 1

I suggest you just use one rule, say format all red and use the CF to change that to green only when there is a match, say with:

=B1=VALUE(RIGHT(A1,4))  

in B1 and applied to B:B.