QUOTE(YetAnotherPianist @ Apr 16 2008, 05:00 PM)

QUOTE(piano*singing*lover @ Apr 16 2008, 02:47 PM)

Does anyone have any suggestions at how to get better at reading rhythm's and playing in time?
Learn some of Bartók's Mikrokosmos. Some of the problems with reading rhythms occur when one thinks too hard about playing them. Bartók's use of non-conventional rhythms forces one to develop an instinctive approach: when a piece is written in (3+3+2/8), one can't think about it, one has to just play it, precisely the technique needed for sight reading.
I lend this to pupils for this very reason, but, sadly, I have yet to find a pupil who will play them willingly....

An ex adult pupil of mine who used to feel very guilty when good weather kept her away from the piano, used to take sightreading books out into the garden and literally 'think' her way through pieces, rhythmically - and it did seem to help. You could combine this type of thing with what Cyrilla suggested, and then a semiquaver, visually, for instance, would just start to imply the 'dee' in 'dum-dee-dum' if it was dotted quaver/semiquaver/quaver - i.e. a dotted rhythm.
It can make life easier if you break things down a bit when sightreading as well - thinking of two groups of four quavers in a bar, for instance, instead of four crotchets. It makes fitting in the semiquavers easier whilst maintaining a steady pulse.