Artificial Leg: Teacher guidelines
This resource could be used in a variety of ways to gather assessment
information.
1. Warmup
The aim of this warmup activity is to set the scene by exploring concepts of
measurement and 3-d models and to explore the context around artificial
limbs. This activity could be adapted to have the students fit the model to a
classmate’s leg rather than use Ann’s measurements.
The warmup activity could be done independently or could be used as a
warmup to the assessment task and completed in groups or as a whole class.
An important part of the warm up is a class discussion to explore the context
of artificial limbs so that all students are familiar with the issues that need
considering (in particular that we are interested in a leg that has a shape
similar to a real leg).
2. Assessment task
The assessment task could be carried out in a test situation or as an
investigation or group project.
Possible formats for presenting the evidence include written report, poster,
presentation to the class.
3. Support material
 Success criteria: to help students develop clear understanding of the
requirements of the standard.
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Mathematical toolbox: the can do list provides a student-friendly
summary of the relevant measurement skills that may be needed to complete
the task.
Tool Box: Level One Measurement
This can do list provides a summary of the relevant measurement skills that
may be needed to complete the assessment task for achievement standard
90130.
Can I?
Convert between metric units for
length: mm,cm,m,km
Convert between metric units for area:
mm2 ,cm 2,m2 ,km2
Convert between metric units for
volume: mm3 ,cm 3,m3 ,km3 hectares,
Convert between metric units for
capacity: mm3 ,cm 3, L mL
Find the perimeters and areas of
polygons.
Find the perimeters and areas of circles
Find the perimeters and areas of
composite shapes
Calculate volumes of prisms
Calculate volumes of pyramids and cones
Calculate volumes of spheres
Calculate volumes of composite shapes
Deduce and use formulae to find the
perimeters and areas of polygons,
Deduce and use formulae to find
volumes of prisms
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You need to use these skills in solving relevant measurement problems.
Success Criteria: Mathematics and Statistics 91030 1.5
Success Criteria for All Students
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Solve measurement problems that may involve calculating:
o Length, perimeter, circumference
o Area (including surface area) of polygons or composite shapes
o Volumes, chosen from
– prisms (more difficult than cuboid),
– pyramids,
– cones,
– spheres.
Demonstrate knowledge of measurement concepts and terms by correctly using
o metric units
o units appropriate for the context.
Success Criteria for Achievement
Success Criteria for Achievement with
Merit
To demonstrate that you can apply measurement
to solving problems, you will
 Decide how you are going to solve the task and
 Communicate your solution process clearly by
o identifying what is being calculated,
o using measurement words correctly and
o using correct names of shapes and solids.
To demonstrate that you can apply
measurement, using relational thinking, in solving
problems, you will
 Form and use a model to solve the task and
 Clearly communicate thinking by
o showing the logical sequence of steps
you used and
o connecting your methods and solutions
to the context.
Success Criteria for Achievement with
Excellence
To demonstrate that you can apply measurement,
using extended abstract thinking in solving problems,
you will
 Form a relevant generalisation of the solution or
communicating mathematical insight and
 Clearly communicate thinking by
o showing the logical sequence of steps you
used and
o connecting your methods and solutions to the
context.
Final grades will be decided using professional judgement based on a holistic examination of the evidence provided against the criteria in the Achievement
Standard.
Warm-up: Ann’s leg
Background:
Biodesigns make artificial legs for amputees. They form a
model that looks like a person’s leg. They use the model to
estimate the amount of material needed. Two different
materials are used, one type for the inside of the leg and one
type for the outside (the skin).
Ann has an artificial leg made. Biodesigns use a simple model based on one
cylinder.
Biodesigns measured Ann’s leg
Leg length: 86cm
Width at widest part: 20cm
Your task is to:
 Calculate the amount of material needed to fill the inside of the artificial
leg.
 Calculate the amount of material needed for the skin.
Discussion:
 What are some of the problems with this model of an artificial leg?
 What things should you consider to make a model that is useful and
“looks” like a leg?
 Do all the surfaces of the model need skin?
 Do you understand the success criteria for the achievement standard?
Assessment Task: Artificial leg
Background:
Biodesigns makes artificial legs for amputees. They form a
model that looks like a person’s leg. They use the model to
estimate the amount of material needed. Two different
materials are used, one type for the inside of the leg and one
type for the outside (the skin).
Biodesigns first used a simple model based on one cylinder:
Biodesigns want to improve the model so that it can bend. They consider
other models including a model made from 4 cylinders, such as:
Your task is to calculate the amount of the material needed for a leg that
bends.
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Use
o the 4 cylinder model above or
o a better model of your own design.
Calculate the amount of material needed for a leg for someone of your
height and build, by
o calculating the amount of material needed to fill the inside of the
model and
o calculating the amount of material needed for the skin for the
model.
Provide a formula to calculate the total amount of material needed for
the model of a leg for someone of any height and build.
You will be assessed on the depth of your mathematical understanding as
shown by the model you use and your solution process.
It is important you communicate your solution process clearly and relate your
findings to the context.
Assessment schedule: Mathematics and Statistics 91030 1.5 Artificial leg
Evidence/Judgements for Achievement
Apply measurement in solving problems.
Students
 communicate solution process by
o identifying what is being calculated,
o using measurement words correctly and
o using correct names of shapes and solids
 select and use at least 3 out of 7 of these
methods in solving relevant problems:
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surface area of
o cylinder,
o sphere,
o cone,
volume of
o cylinder,
o sphere,
o cone,
Evidence/Judgements for Achievement with
Merit
Apply measurement, using relational thinking, in
solving problems.
Evidence/Judgements for Achievement with
Excellence
Apply measurement, using extended abstract
thinking, in solving problems.
Students
 form a model; accept any model that is more ‘fit
for purpose’ than a one-cylinder model
 find amount of the two materials needed for
their model (do not penalise minor errors)
 and clearly communicate thinking by
o showing the logical sequence of
steps used and
o connecting methods and solutions
to the context.
Students
 form a relevant generalisation by finding an
expression for the total amount of material
needed for any model of a leg for any
dimensions.
 and clearly communicate thinking by
o identifying variables used,
o showing the logical sequence of steps
used, and
o connecting methods and solutions to the
context.
 or communicating mathematical insight
 use appropriate metric units.
Final grades will be decided using professional judgement based on a holistic examination of the evidence provided against the criteria in the Achievement
Standard.