group is given a basket of objects, with examples of each of the categories
might include: clear jars/bottles/containers; plastic lunch-boxes or tumblers
(you could find examples of all 3 categories among these); coloured clear
plastic (e.g. wrapping on Lucozade bottles); wood; cloth; cling-film;
foil containers; cooking foil; thick paper; thin paper!; card; paper plates;
tracing paper; grease-proof paper.
the pupils a few minutes to explore the objects/materials which they've
ask each group to come up with a way in which they might sort the objects
into 2 sets or categories.
them to call you over when they've agreed on a way of doing this.
this stage, the pupils might choose criteria such as shape, colour, texture,
visit each group of children, ask them if they were all in agreement on
the categorisation of the materials.
out whether there were any materials which they found hard to assign to
ask them to come up with another way of sorting the objects into 2 sets
could tell them that it may sometimes be necessary to invent a 3rd
each group has sorted the materials along a couple of different lines,
get the attention of the whole class and ask them to list the various ways
in which the objects might be sorted. These could be written on the board.
They may include
pupils don't suggest 'see-through'/ 'not see-through' as an option, suggest
it yourself at this point. Ask each group of pupils to sort the objects
into 2 sets: those through which they can see and those through which it
is impossible to see.
stage, the pupils should have warmed to the skills involved in the task.
They should also have had to deal with objects/materials which were difficult
to fit into the given categories. There may not be unanimous agreement
in every group with regard to the sorting process. Encourage pupils
to discuss the differences of opinion which emerge.
might take place along the following lines:
wrapping on Lucozade bottle)
children may even be confused by the foil
haven't done so already, you could now introduce the torches and tell pupils
that they may use them to help with the sorting activity.
you go from group to group, introduce the terms transparent and
elicit these from the children). Get the pupils to write each word
at the top of a column in their notebooks and to list the objects which
fall under each heading.
now, the pupils will have become aware of a third category. There are some
materials through which you could see the torch shine, or through which
daylight might be visible. Yet these aren't transparent.
you feel that your class is up to it, you could introduce the term translucent
this stage and ask pupils to list the items which fall into this category.Closure
the whole class together again (withdraw the materials if necessary) and
recap on what has been learned.
pupils are up to it, check if they see any significance in the fact that
the materials which didn't let the torch light through are also the ones
through which we can't see. This might nudge them towards a more scientific
idea about how our sense of sight works. Or it might confuse them