Adding and subtracting fractions

Adding and subtracting fractions

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

a)
 
In a team race, Kylie ran 14 of a kilometre and then tagged Joshua who ran for 18 of a kilometre.
 
Altogether, what fraction of a kilometre had they run? __________
 

 
 
 
b)
Marie and Liam shared a pie. Marie ate 13 of the pie and Liam ate 15 of the pie.
What fraction of the pie
 
 

i)
 
ii)

 
... did they eat altogether? __________
 
... was left over? __________
 
 
 
c)
 
Wiremu had 37 kilogram of cheese. He was given another 25 kilogram.
 
What fraction of a kilogram of cheese did Wiremu now have? __________
Task administration: 
This task is completed with pencil and paper only.
Levels:
4, 5
Curriculum info: 
Maths, Number and Algebra, Number Strategies
Keywords: 
fractions, addition
Description of task: 
Students solve number problems involving the addition and subtraction of fractions.
Learning Progression Frameworks
This resource can provide evidence of learning associated with
Additive thinking, sets 7-8
Additive thinking, sets 7-8
within the Mathematics Learning Progressions Frameworks.
Read more about the Learning Progressions Frameworks.
Answers/responses: 

 

Y10 (11/2000)
a)   3/8 easy
b) i) 
ii)		 8/15
7/15   [accept 1 - b)i)]		 moderate 
easy
c)   29/35 moderate
Diagnostic and formative information: 
 

Common error

Likely calculation

Likely reason

a) 
b)  i) 
c)

2/12 (or 1/6)
2/8 (or 1/4)
5/12

 

Wrong addition of fractions.

c)

6/35

 

Confuses addition and multiplication of fractions.