If you want to find out more on place value you can go here.
Place value is one of those areas where children can really get stuck. They need to have a good understanding of this area if they are to move forward with their maths. One of the first things I get children to do is make a picture of a number.
Once they are getting to grips with the fact that a 1 in the units is different to a one in the tens column I will introduce a place value chart so that they can really see what each column represents. I use something similar to this so that even from the very beginning children are seeing the pattern in place value. There's simply no point in teaching them Th/H/T/U because there is no pattern there, so it only hinders them.