Rich tasks
Make your own device
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1. Make your own device
- Encourage students to do some research into measuring devices. This could include measuring devices from history or other cultures, to give them ideas for the devices they are creating.
- Remind students that as well as making the device they also need to create a presentation.
- Provide students with an opportunity to share their devices and explain their presentation to others. This sharing could be done to the whole class or teachers could make up smaller groups, for example, so that length, weight and capacity are represented in each or so that students can compare different devices for measuring the same attribute.
Units of measure page 192
- Know the standard units of length and the smaller units that are derived from them for length, weight, capacity.
- Understand that for everyday use temperature is measured in degrees Celsius.
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Teacher notes
- Researching the metric system may be a useful extension task for interested students. Understanding that the metric system works in multiples of ten similar to the decimal system is helpful for some students. Prefixes give an indication of increasing or decreasing size.
Length is a good example to use for discussion:
10 mm = 1 cm
100 cm = 1 metre
1000 m = 1 kilometre
Choosing units page 195
- Use appropriate units of measurement for different tasks.
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Teacher notes
- Students should first identify which unit to use. For example, metre for length, kilogram for weight, litre for capacity, and then decide the appropriate scale.
Reading scales page 197
- Read scales to the nearest mark on a range of measuring devices.
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Teacher notes
- Students should be encouraged to look at the unit used on the measuring device first, and then the scale.
- Remind students frequently that including the unit is a very important part of their answer. You may like to acknowledge the students who do include the unit of measure to indicate the value of this convention.
- At this level, students should read to the nearest mark, rounding down for units that are below half way and up for units at or above halfway.
- Encourage students to count / skip count increments between numbers (where some marks don’t have numbers), to ensure that they have interpreted the scale correctly.
- Having students copy / draw a scale requires them to observe details closely and is a worthwhile independent activity.
- Again, giving students opportunity to use actual measuring devices is very important as they are often more complex in real life. For example, a ruler or measuring jug may show both decimal and imperial units and students may need support in finding the metric scale which they should use.
- If there are insufficient measuring devices for all students to measure the same attribute at one time, a cycle of tasks at different workstations around the classroom is a useful approach, for example, teachers may set up a variety of length, capacity or weight problems to engage with and rotate groups of students around. While this takes a while to set up, it may also require more than one session for students to fully engage with all of the activities.
Estimating and measuring page 198
- Make reasonable estimates before measuring with a range of measuring devices.
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Teacher notes
- Establishing benchmarks helps students make more accurate estimates. Students should be encouraged to build their own collection of benchmarks for each unit of measurement they encounter. It is important that students create their own benchmarks from things that are familiar or have meaning for them. This means providing opportunity to discover the length, capacity, weight or temperature of familiar objects that they can then use to compare with other objects. For example, students might suggest the width of a finger or the span of their arms as a benchmark for centimetres and metres.
- It is important that students understand that a ‘good estimate’ is close to, rather than an exact measurement. Teachers should celebrate a close estimate with enthusiasm making it clear that getting the exact measure is not the intention.
- It is helpful to discuss a range that could be considered a ‘good estimate’. This will depend on the unit and object being measured. For example, within a few mm may be a reasonable range for estimating the length of an insect but would be unreasonable if estimating the height of a goal post.
- Opportunity to engage in measuring tasks using a range of measuring devices is essential, not only because measuring accurately is a skill which requires practise, but also because it familiarises students with the unit and scales appropriate for different tasks.
Calculations with measures page 208
- Use addition, subtraction or known multiplication facts to solve problems that combine or partition like measures.
- Record the strategies used and solutions using numbers and units.
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Teacher notes
- Provide students with opportunities to use real measuring devices to combine and partition quantities. Students will need to combine measures if the device they use is smaller than the object being measured, for example , small rulers to measure longer lengths, and partition where the device is larger, for example, a full jug poured into smaller glasses.
- Ensure that students know to use the same unit to add or subtract quantities when working independently, and that they record their thinking.
- There are collections of other optical illusions involving perceptions of size or quantity in books and online. Students who are interested may enjoy finding further examples or researching some of these to find out why they occur.
Angles page 210
- Recognise full, half and quarter angles of turn.
- Know that the unit for measuring angles of turn is a degree (º)
- Understand how angles of turn are used on an analogue clock.
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Teacher notes
- Recognising the angle of a quarter turn and half turn is important for students learning to tell analogue time. Remind students that hands on clocks always move to the right or in a clockwise direction. Students can be learning that a ¼ turn on an analogue clock is equivalent to 15 minutes, and a ½ turn is equivalent to 30 minutes.
