Teaching place value has been the bane of my last few years teaching. I even wake up during the night thinking about them! However, some things that I have found helpful are the place value games on ict. games .co Having a display on a rocket -sets of tens and the units on different parts, having the tens house and the units house- again similar- two houses drawn. Linked to Big Brother- when you have 10 or more you have to leave the units house. When adding tens and units using materials, put the first set upstairs in the tens and unit houses then add the second number by laying out the materials downstairs in the tens and unit houses. With a partner , playing the make 50 game. Sets of tens and units and a dice - exchage as you add on until you reach 50 or whatever number you choose. With subtraction it's just the reverse, lose 50. Hope this makes sense, it would be easier with pictures. At the end of the day it's not easy. Once I feel children are quite confident using the materials we move on to using the number line, much simpler and takes less time.How sad am I doing this at 8.30 on a Friday? Good luck with teaching place value and hopefully some others will come up with better ideas.