The purpose of this unit is to have students identify a need, plan a response, seek feedback, design and build a ‘product’, applying number, measurement and technology knowledge and skills.
When students are comfortable with and efficient in measuring and estimating using appropriate standard units, their learning experiences should provide them opportunities for practical applications of their knowledge and skills. This is the focus of these sessions.
At level 4 students are consolidating their understanding of measurement units of length, kilometre, metre, centimetre, millimetre, they are applying their knowledge and skills using rulers and tape measures, and making conversions between metric units using whole numbers and commonly used decimals. As they engage in practical tasks and use measuring devices, they refine their ability to estimate approximate measurements and to read scales with accuracy in order to make precision measurements to the nearest millimetre.
As students draw plans they learn to apply a scale factor as they reduce three-dimensional shapes to two-dimensional mathematical drawings in which the invariant properties are recognised. As students create a product from a scale plan, they apply the inverse scale factor to the measurements of the product’s component parts.
In the construction tasks, students are also required to apply their understanding of angle. They should be able to read a protractor to the nearest degree, build on their level three understanding of right angles, obtuse and acute angles, and know the degree value of angles that are simple fractions of a whole turn of 360°. For example, as a student uses a bevel angle tool to gauge the inner angle between a sloping table leg and the table top they recognise an acute angle that must be kept the same for each of the four table legs. This angle can be accurately measured with a protractor, and the bevel tool can be set at the desired angle. Students will have opportunities to discover the advantages of using a set-square to ensure that appropriate corners in the construction are 90°.
Students need to ensure that their recording of measurements is accurate and that appropriate abbreviations and symbols are applied.
As students are calculating metric conversions between length measurement units, and as they work with prices and quantities, they will be applying their knowledge of decimal place value, using known multiplication facts and applying a range of advanced additive and multiplicative number strategies.
Associated Achievement Objectives
This unit involves the practical construction of a (wooden) ‘utility item’ for the school. (For example: a picnic table, an outdoor seat or bench, a small shelter fence, a bird table or nesting box, a small junior cubby house, a garden planting box.)
In implementing this unit, consider the size and management of the participant group. There are many implementation possibilities, but you may like to consider one of these three models:
This session is about having students recognise that there is a need or opportunity to create a ‘utility item’ to enhance the school environment.
Prior to the lesson
This session is about students using expert advice to inform detailed scale plans of a particular design and a construction budget.
Prior to the lesson:
Begin by introducing the expert (carpenter) to the class.
Recognise the four most popular product designs and display the survey sheet. See Session 1, Activity 3.
Have the four ‘winning’ designers explain their features and any construction details they had in mind.
Make paper and pencils available. Suggest that students take notes about each numbered design.
Make paper, pencils and rulers available.
Have students each select their personal favourite of the four options, and draw a detailed scale plan of this. Suggest that students use a 1cm:10cm scale.
They should take into account the measurement dimensions (and construction materials suggested by the expert).
Before they begin.
A. Discuss and use questions to elicit from students an understanding that scale is:
That a scale plan is:
Have students give examples in which the scale factor is 1/10. For example:
1/10 or 0.1 of (x) 1.5m or 150cm in real life is 15cm on the scale drawing
1/10 or 0.1 of (x) 0.8m or 80cm in real life is 8cm on the scale drawing
If the expert’s measures include inches, discuss imperial measurement.
Explain that in construction a 4 x 2 (four-by-two) used to be a commonly heard measure. It referred to 4 inches x 2 inches.
It has been suggested by some sources that the origins of the British Imperial system were based on the human body with an inch being a ‘thumb’, a foot, or 12 inches, being a foot and a yard being the distance between your outstretched hand and your nose.
Other suggestions have agricultural references such as an inch being three barleycorns.
Explain that this is the system of measure in the USA.
|Imperial (or US)||Metric|
|1 inch||2.54 cm|
|1 foot (12 inches)||0.3048 m|
|1 yard||0.9144 m|
|1 mile||1.6093 km|
|Metric||Imperial (or US)|
|1 mm||0.039 inches|
|1 cm (10 mm)||0.39 inches|
|1 m (100 cm)||1.093 yards|
|1 kilometre (1000 m)||0.621 miles|
Allow time for the students to develop their scale plans.
Make available to each student a copy of Attachment 1. Discuss.
Have students who have drawn the same design form pairs work together, using the price list for current supply prices for the building products, and prepare their own budget showing estimated costs for the construction materials for their design.
Have students who promptly complete 6, deliver the survey information sheets to the other classes in the school, asking for time to explain the project and asking that the classroom teacher give an opportunity for students to vote on their personal design preference.
Ask the teacher to record on the sheet the number of votes for each design.
Make available copies of Connected 3, 2005, p2. Our Pātaka, for the students to read and consider.
This session is about planning a fundraising venture to pay for the planned ‘utility item’.
Prior to the session:
Identify the design that is preferred by the other students in the school.
Take notice of any additional suggestions. Discuss the merits of any deserving of consideration.
Have students who drew a scale plan for and prepared a budget of estimate of costs for this design, share their plans and budgets.
Have students justify and explain their plans and costs.
This session is about applying precision measurement skills to complete the construction of the ‘utility item’.
Whilst key teaching points are detailed, the practical implementation will depend on the actual fund raising plan, the construction project and the classroom organisation.
Photograph the construction as it proceeds.
Prior to this session:
Confirm the BOT decision with the students and discuss the implementation plan for both the fundraiser and the building project.
Before construction begins, explore each measuring device and have the students to model precision measurement with each.
Place in front of the student a range of relevant measuring devices.
Adjustable bevel angle tool
Review safety instructions relevant for construction tools being used. For example hammers, saws, drills.
Have students check all building materials against the order list.
Proceed with construction.
This session is about students evaluating the product, the process and on the mathematics that they have applied.
Prior to the session:
Make copies of photos of the production process and finished product available to each student (digital or hard copies.)
Have students make annotated posters documenting each stage of the construction process, including the specific mathematics applied at each step.
Have students critique the process and financial outcomes of their fundraising plan, including specifically evaluating their profit calculations and predictions.
Have students host an event to ‘launch’ the product.