On the Slippery Slope This is a level 3 measurement activity
from the Figure It Out theme series. measure time using a
stopwatch measure lengths with a tape measure discuss patterns
found in results The students will need to use cardboard that is
flexible enough to curve evenly along its length. Strong
cartridge paper or poster card is about the right thickness. As
well as being 80 centimetres long, the cardboard needs to be at
least 30 centimetres wide so that the marble is less likely to
roll off the side. The students also need to make sure that when
the cardboard is set up between the books, it doesn’t slope to
one side because this could make it roll off the side. Discuss
the following potential problems with the students before they
start the investigation: • How will they decide when the marble
is finally at rest? (This should be when it stops moving up and
down the ramp.) • How will they cope with variable measurements?
(One approach is to take three or five measurements and use the
middle measurement