A spot of sickness
This is a level 2 algebra strand activity from the Figure It Out series. A PDF of the student activity is included.
About this resource
Figure It Out is a series of 80 books published between 1999 and 2009 to support teaching and learning in New Zealand classrooms.
This resource provides the teachers’ notes and answers for one activity from the Figure It Out series. A printable PDF of the student activity can be downloaded from the materials that come with this resource.
Specific learning outcomes:
- Continue a sequential pattern.
- Show a pattern on a graph.
A spot of sickness
Achievement objectives
NA2-8: Find rules for the next member in a sequential pattern.
Required materials
- Figure It Out, Levels 2–3, Algebra, "A spot of sickness", page 9
- counters
See Materials that come with this resource to download:
- A spot of sickness activity (.pdf)
Activity
Counters and faces drawn on pieces of card are essential for this activity. They enable students to construct the graph in Activity 2.
Students will need to count the number of chickenpox spots carefully, as any errors will obscure the pattern. Organising the information in a table is helpful.
Day |
Monday |
Tuesday |
Wednesday |
Thursday |
Friday |
|---|---|---|---|---|---|
Number of chickenpox spots |
1 |
3 |
5 |
7 |
9 |
The number pattern makes it clear that the number of chickenpox spots is growing by two each day. Other answers are possible, as long as they can be justified. For example:
- I think Jerry has six chickenpox spots on Friday because he is getting better, and he loses the first chickenpox spot he got.
This activity requires students to draw a graph of the relationship between the days of the week and the number of chickenpox spots on Jerry’s face. It is conventional to show such relations as points on a number plane, as in the example below. This means that a point at the top of each column of counters is sufficient. It is also conventional to have the independent variable (the one we have knowledge of) on the horizontal axis and the dependent variable (the one we are trying to find out about) on the vertical axis.
In this activity, students’ graphs will vary, but encourage them to explain their graphs to others to facilitate peer assessment. It is vital that students explain the position of points to establish whether or not they understand ordered pairs.
Activity 1
1.
a. 9
b. Each time, Jerry adds two more spots.
2.
It will have 11 spots on it.
Activity 2
1.
Answers will vary.
2.
My Chickenpox Graph
3.
Answers will vary. One idea is to mark dots on the paper where the counters were.
4.
Two extra spots each day make a diagonal pattern.
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