Area of shapes II
0
Overview
Using this Resource
Connecting to the Curriculum
Marking Student Responses
Working with Students
Further Resources
This task is about area.
Task administration:
This task can be completed with pen and paper or online (with automarking).
Levels:
3, 4
Curriculum info:
Keywords:
Description of task:
Students work out the area of different shapes.
Curriculum Links:
This resource can be used to help to identify students' understanding of the measurement of area.
Learning Progression Frameworks
This resource can provide evidence of learning associated with within the Mathematics Learning Progressions Frameworks.
Read more about the Learning Progressions Frameworks.Answers/responses:
Y6 (10/2013) 

a) 
12.5 
moderate 
b) 
8 
moderate 
c) 
8 
moderate 
d) 
7.5 
moderate 
Based on a sample of 50 Y6 Students
NOTE:
+/ 0.5 units is a margin that allows students a margin of error as the requirement of the understanding that a diagonal drawn through two or three squares is equivalent to half the number of squares is a curriculum level 4 understanding.
Diagnostic and formative information:
Common error  Likely misconception  
a)
b)
c)
d)

12 [0.5 range: 1213]
7.5 [0.5 range: 7.58.5]
7.5 [0.5 range: 7.58.5]
7 or 8 [0.5 range: 78]

Students may not be aware that a diagonal drawn through two or three (or similar group of) squares is equivalent to half the number of squares. Therefore the estimation/calculation has a margin of measurement error.

a)
b)
c)
d)

24/25
1516
1516
1215

Students count the "half unit squares" and write this as their answer. Note: this may also involve the above measurement error with a higher margin of error. 
Next steps:
For students who counted the "half units" instead of whole units may need more understanding of what a unit square is by exploring simpler tasks that explore building up unit squares. The resource How many Xs cover Y looks at superimposing unit squares onto shapes.
For students who worked out the area with a wider margin of error due to working with the halfdiagonal unit squares, the resource Triangle areas and Area of two shapes look at working out unit squares with simpler diagonals (note: cm^{2} is used). The resource Working out area addresses trying to find the unit area with curved shapes  looking at this is a good way to explore the difference between working out straight diagonals and having to estimate for curved sides.