Help!! I've just returned from maternity leave to take over a Year 3/4 class of VERY mixed ability. Many of them have absolutely no concept of place value and without that, as you know, they're pretty much stuck. Therefore, I need to do, do and do some more place value work so I'd really welcome your ideas. I'm going to have to stick with it for a while, so the more ideas the better - right from the basics upwards, mental starters, practical activities, anything you have done that's really worked for you. Many, many thanks in advance!