Music playlist

Music playlist

Pencil and paper
Overview
Using this Resource
Connecting to the Curriculum
Marking Student Responses
Working with Students
Further Resources
This task is about percentages.

 

a) i)
Patrick finds that 80 percent of his playlist is rap music.
 
If he has 120 songs altogether, what number are rap? ________
 
ii)
 
Alice finds that 60 percent of her playlist is mixed, and the rest are classical music.
 
If she has 180 songs altogether, what number are classical? ________

b)
i)

Hing has 220 songs on her playlist, and 165 of them are disco music.
 
What percentage of Hing's playlist is disco? ________ %
 
ii)

 

 

Alisa has 140 songs on her playlist, and 98 of them are hip-hop. The rest are techno.
 
What percentage of Alisa's CDs are techno? ________ %
Task administration: 
This task is completed with pencil and paper only.
Level:
4
Curriculum info: 
Maths, Number and Algebra, Number Strategies
Keywords: 
percentages
Description of task: 
Students calculate percentages of whole numbers and convert fractions to percentages.
Curriculum Links: 
This resource can help to identify students' ability to apply additive or multiplicative strategies flexibly to obtain percentages of whole numbers.
Learning Progression Frameworks
This resource can provide evidence of learning associated with
Multiplicative thinking, sets 6-7
within the Mathematics Learning Progressions Frameworks.
Read more about the Learning Progressions Frameworks.
Answers/responses: 
 

Y9 (03/1999)
a) i)
ii)		 96
72		 very difficult
very difficult
b) i)
ii)		 75
30		 very difficult
very difficult
Diagnostic and formative information: 
  Common error Likely calculation Likely reason
a) i)
    ii)
b) i)
    ii)		 40
120
55
42		 120 - 80
180 - 60
220 - 165
140 - 98		 Incorrect concept of percentage or simply subtracting numbers in text from each other.
a) ii)
b) ii)		 108
70		 0.6 × 180
(98 ÷ 140) × 100		 Number of mixed songs.
Percentage of hip-hop songs.
a) i) 100 120 - 20 Subtracts 20 because 80% is 20 less than 100%.