To understand that the number of objects stays the same when they are moved about whether close together or spaced out.
This is when children can count a cluster of objects successfully but if the size of the object changes or the layout is more spreadout (even if the child watches the manoeuvre) they think the number of objects must be bigger or smaller.
It is crucial that children understand that the size of objects or their layout makes no difference to the number being counted.
Combined with 1-1 correspondence, these are the initial concepts within counting that have to be embedded so that the next concepts can be learnt successfully.
Use a number of objects, for example, 5 buttons and arrange them into different patterns counting the buttons each time to reinforce the concept that it doesn’t matter how many time the objects are moved the amount always stays the same.
Counting objects in a particular layout using 1 – 1 correspondence and then letting the child move them into another layout.
How many buttons are there now?
In the beginning children will need to count the buttons again to make sure.
Eventually they will ‘know the number hasn’t changed and you’ll get the look – you know the one I mean -‘Are you daft? Of course the number is still the same’ look. It is usually accompanied with a roll of the eyes. Look on this as a positive because they have ‘got it’.
I’m sure that if I looked hard enough I could find resources to the learning of conservation of number but, in all honesty, they aren’t needed.
Count whatever you have at home and change the layout to help children learn the concept.
Cheap, cheerful and effective.
Use a variety of objects changing the layout, location, size etc.