Depth time graphs of filling different containers. (GeoGebra). Simply select the container you want and the speed of animation, select animate and watch the graph.
From the GeoGrebra resource team, a resource to interpret meanings of different rates of change across a graph that represents the water level in a hot tub.
From Michigan State University’s Connected Maths Project Student Activities, one of the Grade 7 Activities is Pouring and Filling which provides a great demonstration of relationships between the volumes of pyramids and prisms. We could tip the contents of a cone into the cylinder for example…
Each activity describes the purpose of the activity and has suggested uses, many activities as this does have helpful how to videos.
These activities are well worth exploring, for example in Grade 6 we have factor and product games and also the very satisfying locker problem. Note the TEDEd lesson video here.
One of the grade 8 activities is the classic Painted Cube. This activity is so clear; it allows students to build a cube or cuboid out of unit cubes, colour the faces using a palette of colours, then rotate the object to paint the initially hidden sides. The expand option allows students to blow up the prism and inspect will count the number of cubes with 0, 1, 2 or 3 painted faces.