Area of 3 fields

Area of 3 fields

Auto-markingPencil and paperOnline interactive
Overview
Using this Resource
Connecting to the Curriculum
Marking Student Responses
Working with Students
Further Resources
This task is about working out area and perimeter.
Tim has some animals that he keeps in three different sized fields.
Three-fields.png
Field Y is a square with an area of 100 m2.

Question 2Change answer

a)  The area of Field X is half the area of Field Y. 
     What is the area of Field X?   m2

Question 2Change answer

b)  The area of Field Z is two times the area of Field Y.
      What is the total area of the three fields?      m2

Question 2Change answer

c)  Tim decides to put a new fence around Field Y.
     To help Tim work out how much fencing he needs, work out the perimeter of Field Y.
     The perimeter of Field Y is m
Task administration: 
This task can be completed with pencil and paper or online (with auto marking displayed to students).
Level:
4
Curriculum info: 
Maths, Geometry and Measurement, Measurement
Keywords: 
area, perimeter, measurement
Description of task: 
Students calculate the area of composite shapes.
Curriculum Links: 
This resource can help to identify students' understanding of calculating perimeter and area for the Measurement Standard and multiplicative strategies.
Learning Progression Frameworks
This resource can provide evidence of learning associated with
Measurement sense, sets 6-7
Multiplicative thinking, sets 6-7
within the Mathematics Learning Progressions Frameworks.
Read more about the Learning Progressions Frameworks.
Answers/responses: 
   

Y8 (05/1998)
a) 50 easy
b) 350 moderate
c) 40 very difficult
 
EXTENSION: Tim then decides to put a new fence around both fields Y and Z. How much fencing in total does he need?
 
EXTENSION ANSWER: 90 m (or accept if d) = c) × 9 ÷ 4). [very difficult]
Diagnostic and formative information: 
  Student response Likely calculation Likely reason
c) 100

200

400

 25 × 4

50 × 4

100 × 4

 Confuses area and perimeter or assumes 
side length of 25 m (= 100 ÷ 4).
Assumes side length of 50 m (= 100 ÷ 2)
(may be confusing area and perimeter).
Assumes side length of 100 m
(may be confusing area and perimeter).