Teacher notes

• At Level 1 students will have experienced measurement by directly comparing one object against another. For example, by placing two pencils side by side to find which is longer. They might have experienced indirect measurement using non-standard units, for example using a row of paperclips to find which of the two pencils is longer.
• Students should be encouraged to develop and consistently apply principles for measuring, whether they are using non-standard units or standard units.
  These principles include:
  • measuring the whole length,
  • measuring with units of equal size,
  • leaving no gaps or overlaps.
• Encourage students to estimate before measuring.
  • It is important that students realise that estimating is not the same as making a ‘wild guess’. There should be some careful thought about how many times the unit being used can be repeated.
  • It is helpful if students understand why estimates are needed. For example, sometimes an exact measurement may not be possible, and having an estimate also allows checking that the measuring has been done correctly and makes sense.
  • Some students will be focused on getting the correct answer when they estimate. It can be helpful to discuss what a reasonable range for a ‘good’ estimate might be. For example, if a pencil was measured using paper clips, students might agree that a reasonable range for the estimation would be 1 paper clip more or less than the actual length of the pencil.
  • When measuring everyday items, it is inevitable that students will find lengths which are not multiples of a whole unit (for example, a bit less than the next cm or a bit more than the last metre). Most students at this level should be encouraged to round to the ‘closest’ centimetre or metre but introducing fractions such as ½ or more accurate units such as millimetres, may be appropriate for some students. Give them the opportunity to tell you what they know by careful questioning.