Here is a number: 3,456. That is one way to write it. But hands up: is there more than one way we could break this same number up and still have exactly the same amount? What would you split off first?

The interactive shows each number built on the place-value mat. Look at how the blocks are piled in each example and keep an eye on whether the total actually changes.

We work through these four on the mat, one at a time. As each number appears, say the value of each column out loud together before we check it. The zeros are the ones that catch people out.

• Partition 4,050 into its columns.
• Build 4,700, then say how many hundreds it is.
• Partition 6,308 into its columns.
• Build 2,300, then say how many hundreds it is.