It's a funny one - and contentious in synthetic phonics camps too. Some would prefer it to be taught as a split diagraph (u_e) rather than as a separate phoneme. It varies from region to region due to pronunciation, doesn't it?
can't really help but I just taught it to my daughter as we came across it so mostly as er and then did sure as an odd one. Sure used to be on the key words I think because it was an exception but I am sure they have now made a phonic rule for it.
Looking at synthetic phonics programmes, 'ure' seems to be taught as an individual phoneme, but I don't know how to pronounce it! Is it just my accent? I pronounce 'sure' in the same way as 'shore' and in 'measure/treasure' the 'ure' is the same as 'er' in 'teacher'.
Can someone tell me a word where it has a clear, different pronounciation, or can I teach it to my DD as being similar to er/ur/ir?