Fraction amounts

Fraction amounts

Pencil and paper
Overview
Using this Resource
Connecting to the Curriculum
Marking Student Responses
Working with Students
Further Resources
This task is about adding and subtracting fractions.
Give all answers as fractions.
a)  Mr Eagles bought 10 pizzas for a party. The males at the party ate 3\(1 \over 2\) pizzas and the females ate 3\(5 \over 8\) pizzas.
 
     i)    Altogether how many pizzas were eaten? __________
 
     ii)   How much pizza was left over? __________
 

 
b)  The amount of water in each bucket is written on it.
 
     Altogether, how much water is there in the two buckets? __________ L
 

 
c)  The amount of paint left in each can is written on it.
 
     Altogether, how much paint is there left in the three cans? __________L
Task administration: 
This task is completed with pencil and paper only.
Level:
5
Curriculum info: 
Maths, Number and Algebra, Number Strategies
Keywords: 
fractions, addition, subtraction
Description of task: 
Students solve addition and subtraction problems involving fractions and mixed numbers with different denominators.
Learning Progression Frameworks
This resource can provide evidence of learning associated with
Additive thinking
within the Mathematics Learning Progressions Frameworks.
Read more about the Learning Progressions Frameworks.
Answers/responses: 
 

Y10 (09/1999)
a)

 

 i)
ii)		 7 1/8 [accept 57/8]
2 7/8 [accept 23/8] [accept 10 - answer to a) i)]		 easy
easy
b)   6 5/12 [accept 77/12] moderate
c)   4 47/60 [accept 287/60] moderate
Diagnostic and formative information: 
  Common error Likely calculation Likely reason
a) i)
    ii)		 8
2		   Works in complete pizzas only.
a) ii)

    ii)
 

 3 7/8
3 1/8		   Subtraction error; equivalent to not renaming.
Subtraction error.
b)
c)
 		 5 5/7
4 3/12, 4 1/4		 3 + 2 = 5; 2+3/3+4 = 5/7
1 + 2 + 1 = 4; 1+1+1/3+4+5 = 3/12		 Doesn't use a common denominator.