Today's lesson is all about finding the difference. As the children get older they will be encouraged (at times) to subtract by finding the difference between two numbers as this is often the most efficient way to calculate. Children often struggle with this concept because they don't really understand the the terms, "how many more?" or "what is the difference?" It's important to start with small numbers whilst they are learning this. Once they are confident with the concept of finding the difference then the number range can be increased.
Building towers with Lego or Duplo can help children to see the difference between two numbers.