Hundreds, tens and units are introduced in Year 2, but if children are to really understand these numbers they need to have a good understanding of place value. For example, in the number 234 the digit 4 has a value of 4 the digit 3 has a value of 30 and the digit 2 has a value of 200. The value of a number is determined by its 'place'. This is an idea that many children fail to appreciate unless they get a lot of practice to reinforce it. It is also important to note that if a digit moves up, one place to the left, it becomes 10 times bigger; if it moves down it becomes ten times smaller. Go to or hundreds, tens and units pages