Sink and float piece of writing!

My classroom has been looking at what will sink in water and what will float.

I really think that it is really cool that we are doing stuff like science just like in the old days for little kids in primary and intermediate.

I'm still not to sure why a 10 ton block of metal will sink but a 10 ton boat made of the same metal will float, I going to read about Archimedes principle.