Cardboard Marble Run

Ask an adult to help cut two or three tubes in half lengthways to make open troughs, and leave the rest whole.

Stand the large cardboard base upright, or lean it against a wall or chair, so you have a tall surface to build on.

Tape your first tube high up near the top, tilting it downhill so a marble would roll along it.

Test the slope by rolling the marble down it, then tape the tube more steeply if the marble stops or moves too slowly.

Tape the next tube just below the end of the first one, angled downhill, so the marble drops from one into the next.

Keep adding tubes lower and lower down the base, checking each one with the marble before you fix the next.

Place a cup at the very bottom to catch the marble when it finishes.

Run the marble from the top and watch the whole journey. If it flies off a gap, move the next tube closer or lower so it catches the marble.