Approach: One
to one |
Level:
Year 4 and year 8 |
|
Focus:
Investigate solubility
rate of different forms of sugar, using a fair test, and explain results. |
|
480k |
Resources: Timer,
packet of raw sugar, packet of coffee sugar, 2 100ml beakers, 2 stirrers, water
in a jug. |
Questions / instructions:
Set out equipment on
table so that it is visible to student.
In this activity you are going to do an experiment to find out which type of sugar
dissolves faster. You should try to make your experiment so that it is a fair
test. |
|
%
responses |
y4 |
y8 |
1.
What do you think we mean in science by a "fair test"? |
a |
a |
|
you keep all features the same except the variable you are trying to find out
about |
7 |
28 |
|
on
the right track, but vague |
37 |
55 |
Let's
begin. Here are packets of two different types of sugar. Carefully tip one packet
of sugar into each beaker. Don't add the water yet. Each packet has the same amount
of sugar. |
a |
a |
2.
What can you tell me about the sugars. How are they different? |
a |
a |
|
not
marked |
a |
a |
3.
Which of these two sugars do you think will dissolve faster? |
a |
a |
|
raw
sugar |
82 |
81 |
|
Why
do you say that? |
a |
a |
|
smaller
crystals dissolve faster |
78 |
78 |
You
need to do an experiment to find out which sugar will dissolve faster. These are
the things that you will need for your experiment.
Point to equipment.
Remember that your experiment needs to be a fair test. |
a |
a |
4.
First of all tell me how you plan to do your experiment so that it is a fair test.
What would you do first?
What would you do next? |
a |
a |
|
Experiment
plan: |
a |
a |
|
use
same amount of water |
49 |
69 |
start
timing as soon as water added (both beakers) |
34 |
55 |
stir
both beakers similarly (schedule & method) |
32 |
51 |
carefully
observe and time until last crystals dissolve |
31 |
47 |
You can do your experiment now. The results sheet is for you to record how long
it took for each type of sugar to dissolve.
Open recording book to results sheet and give it and pen to student, then allow
time. |
a |
a |
5.
What did your experiment show?
Which sugar dissolved faster? |
a |
a |
|
|
raw
sugar |
85 |
90 |
6.
Why do you think this happened?
Why did sugar dissolve faster than the other sugar? |
a |
a |
|
|
not
marked |
a |
a |
7.
If you were to do this experiment again, is there anything that you would do to
make it a better fair test? |
a |
a |
|
|
not
marked |
a |
a |
Commentary:
Year 4 and year 8 students were equally capable at predicting the result of the
experiment and the associate reasons, but year 8 students were better at understanding
and designing a fair test. |