Here is a song about hundreds, tens and ones...
Here are some links to interactive games you can do:
http://www.bbc.co.uk/schools/starship/maths/games/place_the_penguin/big_sound/full.shtml
http://www.topmarks.co.uk/Flash.aspx?f=PVChartv8
http://www.bbc.co.uk/schools/starship/maths/games/place_the_penguin/big_sound/full.shtml
http://www.topmarks.co.uk/Flash.aspx?f=PVChartv8