Another Introduction to Length Lesson – Years 3/4


This lesson introduces students to the concept of measurement focusing on centimetres and metres. It was designed for a year 3/4 composite class, has been tested and worked well as an introductory lesson to assess students current understanding and gaps in their learning to assist in the development of future lessons.

Australian Curriculum Links:

  • Year 3: Measure, order and compare objects using familiar metric units of length, mass and capacity (ACMMG061)
  • Year 4: Use scaled instruments to measure and compare lengths, masses, capacities and temperatures (ACMMG084)


Warm up: Provide students with the following problem:

Sally and Peter were moving into a new house and wanted to see where they could fit their lounge in their new lounge room. They measured the length of the lounge with their feet. Sally measured the length of the lounge as 8 ½ feet long. Peter measured the length of the lounge as 7 feet long.


  • Students think-pair-share the following questions:
    • Why did Peter and Sally get different measurements?
    • How can Peter and Sally ensure they get the same measurement?
  • Show a visual representation of the size difference of Sally and Peter’s foot.
  • Explain that we need a standard unit to measure objects that everyone knows. Introduce centimetres and metres as standard units.
  • Discuss centimetres and metres; write a definition of these, and show them on a ruler.
  • Discuss and demonstrate how to line up a ruler correctly and that we begin measuring at 0 not 1.


  • Students measure various objects around the room in centimetres and metres to practice their measuring skills.


Observation and checklist recording students understanding of the need for standard units and an understanding of how to measure objects using centimetres and metres. Student responses may also be recorded. This assessment has been designed to evaluate students’ current understanding and gaps in their learning that need to be addressed in further lessons.


  • Whiteboard
  • Whiteboard markers
  • Student work books
  • Several centimetre and metre rulers
  • Sally and Peter’s foot templates (or two different sized feet traced and cut out)

sally and peter's foot



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