This problem solving activity has an algebra focus.
In a class there are 20 students. They are wearing jerseys of 3 different colours – blue, green, and red.
The class was lined up in a way that the pattern of jerseys was:
blue, blue, green, green, red, blue, blue, green, green, red...
What colour jersey is the last child in the class wearing?
How many students in the class are wearing a red jersey?
This problem involves recognising and continuing a 5 term repeating and sequential pattern. It also introduces the concept of multiples of 5 as every fifth child is wearing a red jumper. Students have to recognise the given pattern and arrange the 20 people in the given pattern to answer the questions.
In a class there are 20 students. They are wearing jerseys of 3 different colours – blue, green, and red. The class was lined up in a way that the pattern of jerseys was:
blue, blue, green, green, red, blue, blue, green, green, red...
What colour jersey is the last child in the class wearing?
How many students in the class are wearing a red jersey?
Ask the students to make up repeating patterns using members of the class. The solution to this will dependent on the problem posed.
The students can solve the problem systematically by writing down a table as below. Students with pre-writing level skills might draw shapes or write letters (i.e. B, G, R) to represent each member of the class (i.e. each term of the pattern).
To answer the questions in the problem, students need to write the numbers 1-20 and arrange the counters for jerseys in the given pattern.
1 | 2 | 3 | 4 | 5 |
BLUE | BLUE | GREEN | GREEN | RED |
6 | 7 | 8 | 9 | 10 |
BLUE | BLUE | GREEN | GREEN | RED |
11 | 12 | 13 | 14 | 15 |
BLUE | BLUE | GREEN | GREEN | RED |
16 | 17 | 18 | 19 | 20 |
BLUE | BLUE | GREEN | GREEN | RED |
On the other hand, the students might notice that the pattern repeats itself every five students. So the first, sixth, eleventh and so on students have blue jumpers. Using this idea all the questions can be answered.
The last child is wearing a red jersey because 20 = 5 + 5 + 5 + 5.
There are 4 red jerseys and they are worn by the students at 5, 10, 15 and 20.
Printed from https://meaningfulmaths.nt.edu.au/mmws/nz/resource/colourful-jerseys at 8:54pm on the 26th February 2024