Volume and water play

I've been meaning for a while to do something with my 3 year old to help him think a little about volume.  It's been sunny and we have been stuck at home due to covid-19 social distancing measures, so it seemed like a good time to try an activity involving pouring water (in the garden!).  The idea behind this was to show him how different containers could hold different volumes, and that you can work out which has a bigger volume by using something that takes on the shape of the container i.e. a liquid.

Choosing the largest container

It was a very simple setup - a bowl of water (I made it slightly warm as it was still pretty chilly outside in March) and various plastic containers I've saved from food or drink.  The challenge was to use the water in the bowl to arrange them in order of volume.


We started out talking about how the volume is the amount of space inside the container.  I asked him which had the largest volume and he immediately picked the right one (because it was really quite obvious given the sizes of the containers I'd given him!).  I asked him how he could be sure, and he filled it up with water but wasn't really sure what to do next.  I asked whether there would be any left in the big yoghurt pot he'd chosen if he poured the water from it to fill one of the other containers.  He thought there would be, and had a go at pouring some into another tub.  Despite some wobbly pouring and water missing the other tub (there's a reason for doing this outside if you can, maybe do it in the bath otherwise!) there was plenty left.  I asked if the same would happen if he'd chosen any of the other containers and he thought it would.  We didn't test it with all of them, but he did try it with the container he thought was next biggest.

Ordering containers

He then went along in order, choosing the one he thought had the next largest volume, and pouring between containers to check.  When filling containers he usually overfills them and lets whatever liquid it is spill everywhere, but as he was trying to find out if all the water would fit, he took a lot more care and didn't slop very much around at all.  He mostly guessed the right order, but two which were similar in size took a bit of pouring back and forth to decide which was larger.  We talked a bit about how the water took on whatever shape the container was, which made it easy to compare the amount of space inside them.

Finished order, from largest volume to smallest

He played doing a bit more pouring once he'd worked out the order and his little brother joined him.  Water went everywhere, and they had lots of fun until the little one emptied a bottle of water all over himself and got upset about it... Still, it was a simple activity which helped the older one think a bit about volume, and it kept both of them happily amused for a while on a day when they'd been squabbling over everything.