MA1-9MG: measures, records, compares and estimates lengths and distances using uniform informal units, metres and centimetres
|Teaching Points||Using the terms ‘make’, ‘mark’ and ‘move’ assists students in understanding the concept of repeated units. By placing a unit on a flat surface, marking where it ends, moving it along and continuing the process, students see that the unit of measurement is the space between the marks on a measuring device and not the marks themselves.|
Recognising that a length may be divided and recombined to form the same length is an important component of conserving length.
It is important that students have had some measurement experiences before being asked to estimate lengths and distances, and that a variety of estimation strategies is taught.
|Language||Students should be able to communicate using the following language: length, distance, end, end-to-end, side-by-side, gap, overlap, measure, estimate, handspan.|
Measure and compare the lengths of pairs of objects using uniform informal units
|use uniform informal units to measure lengths and distances by placing the units end-to-end without gaps or overlaps|
|– select appropriate uniform informal units to measure lengths and distances, eg paper clips instead of pop sticks to measure a pencil, paces instead of pop sticks to measure the length of the playground (Problem Solving)|
|– measure the lengths of a variety of everyday objects, eg use handspans to measure the length of a table (Problem Solving)|
|– explain the relationship between the size of a unit and the number of units needed, eg more paper clips than pop sticks will be needed to measure the length of the desk (Communicating, Reasoning)|
|record lengths and distances by referring to the number and type of uniform informal unit used|
|– investigate different informal units of length used in various cultures, including those used in Aboriginal communities (Communicating)|
|compare the lengths of two or more objects using appropriate uniform informal units and check by placing the objects side-by-side and aligning the ends|
|– explain why the length of an object remains constant when units are rearranged, eg ‘The book was seven paper clips long. When I moved the paper clips around and measured again, the book was still seven paper clips long’ (Communicating, Reasoning)|
|estimate linear dimensions and the lengths of curves by referring to the number and type of uniform informal unit used and check by measuring|
|– discuss strategies used to estimate lengths, eg visualising the repeated unit, using the process ‘make, mark and move’ (Communicating, Problem Solving)|