Ask child if they’ve ever played with a marble run before, or marbles in general.
What makes a marble go?
How does a marble steer?
In a marble run, what sorts of things influence the marble?
Explore/Explain:
Work together with your child to build a marble run. You can build a tower of varying heights according to the pictures below (alternating 1x4s).
Lead child in making the top connectors and corner turns (a 2×4 and 2×2 tile down the center of a 4×4 plate with corresponding plates underneath to create the grooves for the toilet paper rolls, framed by 1×4 bricks to keep the marble centered; corner turns are similar but on 8×8 plates).
Child can put the towers together in groups, line them up and connect them with toilet paper tubes and start testing their work. Questions to consider:
How far does the marble go?
Why does it get stuck where it does?
What happens when you change the order of the towers?
If there’s a marble of a different size, how does that impact things?
What’s the minimum height difference necessary to make the marble go?