YEARS 7–12 IDEAS FOR THE CLASSROOM
Year 7 Practical Skills for Inquiry Learning – Part 3 (continued)
• When they have worked it all out and cleaned up their mess,
their task is to think through what they did and find a way
of recording it effectively. You might choose to get them to
do a limited word poster again to share with the class, as
this really makes them think about how to communicate all
the necessary information succinctly. A flow chart could also
work well.
Requirements:
For each group
• sherbet sweets e.g. fruit tingles (you must check your
school’s rules on this)
• samples of the main ingredients of the sweets, if possible
in small plastic lidded containers:–
• It is while they are doing this that you can help them to think
more systematically about what they did and, if necessary,
encourage them to suggest improvements. Why did they do
what they did? What steps did they take? ….. (it is by getting
students to think through the steps and make them explicit,
that eventually helps them to develop an understanding of the
‘scientific method’)
– bicarbonate of soda labelled A;
– citric acid labelled B;
– sugar labelled C;
– (they also contain small amounts of colouring and
flavouring agents)
• access to the usual lab apparatus (except heating
equipment) – you may like to put out a selection for
them to choose from as a means of limiting the chaos!
Alternatively, just supply test tubes, racks, stirring rods
(any new pieces of apparatus need to be added to the
list in the back of their note books).
• You will need to share the groups’ posters or flow charts –
consider passing them round from group to group so that they
can compare them, or put each on a separate desk and let the
groups wander round checking them (as alternatives to each
group presenting out the front of the class). You will need to
try and gather the ‘class best ideas’ about how to solve the
problem, remembering that you are trying to help them ‘arrive
at’ (but not to tell them) the scientific method. However, it is
very important not to ignore their ideas and impose your own
– they are unlikely to have worked it all out yet, but may well
be ‘on the way’. You will be providing many more activities
in the future for them to develop their ‘fair test or scientific
method’ ideas, but for them ultimately to be able to genuinely
understand the scientific approach and apply it in any
situation they MUST work it out for themselves.
• A3 paper
• Pens – various colours
What the teacher does:
I realise that using and eating a sweet could pose a problem in
some cases, so you must decide whether to amend the procedure
or perhaps omit the activity altogether. It is certainly more fun to
put the sweet on your tongue and then inside your mouth, rather
than on a watch glass and adding drops of water to it!
• You may also like to get students to discuss the good features
of some posters and the things which could be improved –
and hence build up some criteria for designing an effective
poster.
• You can introduce the activity by giving each student a sherbet
sweet to place on their tongue, which they have stuck out and
leave out! – (no fizzing) – and then ask them to draw their
tongue in and suck the sweet. Get them to describe what the
tongue feels – especially the fizz.
• Ultimately, we will want our students to write a traditional
scientific report, but that does not mean every activity needs
to be written up this way, or indeed at all. Indeed, to insist on
this detracts from the practical and puts students off, as the
chore of always writing a formal report takes much of the fun
out of the activity. It is important to let them write up activities
initially as they choose to, and you may be surprised to see
that they often are writing up what we want anyway. When
this happens we can begin to formalise it and give the usual
headings etc.
• Their task is to work out what causes the sweets to fizz using
the samples of the 3 main ingredients (A, B, C), which you
provide for them.
• They will have to realise that fizzing only happens when they
sucked the sweet – which is the clue that water is also needed
– or they won’t progress very far. Avoid telling them this. (The
fizz is due to carbon dioxide gas being evolved when the
citric acid – which needs to go into solution – reacts with the
bicarbonate).
• It is also important to realise that some activities do not need
to be recorded at all – and of those that do, we should let
students use a variety of methods of reporting them. They
need to learn to record their work in different ways and for
51
SCIENCE EDUCATIONAL NEWS VOL 68 NO 3