Measuring stem circumferences

RHS School Resource
Develop observation and data collection skills while exploring plant growth.


Measuring the circumference of a tree branch

Quick facts

Learning objectives:

Measure stem circumferences accurately in cm and mm

1

Solve gardening-focused problems, converting between m, cm and mm

2

Create problems based on conversion between m, cm and mm

3

Maths: Measure and compare lengths in m, cm and mm

4

Key vocabulary

Circumference | Stem | Staking | Metre | Centimetre | Millimetre | Convert

Equipment

Introduction

Set a challenge to calculate amounts of string needed to stake stems across the garden to prevent wind damage.

Demonstrate stem circumference measurement by:

  1. Wrapping string around a stem and holding the place where the string meets
  2. Accurately measuring the amount of string used using a ruler

Main activity

Pupils work in pairs accurately measuring and recording the circumference of a variety of stems using string and a ruler.

  • Pupils complete a recording table converting between m, cm and mm
  • Pupils use their recording table to answer measurement problems and generate new problems

Plenary and assessment questions

Plenary

Invite pairs to share their new measurement problems.

Assessment questions

  • Was it easier to record the stem circumferences in m, cm or mm?
  • What advice would you give someone who wanted to measure the circumference of a large tree trunk accurately?

Additional information

This activity provides an opportunity to learn outside with plants as a route to developing maths understanding and provides a real-life context for learning.

The activity offers an opportunity for pupils to have hands-on experience selecting which plant stems they would like to measure and to consolidate their understanding by measuring the circumference of a variety of stems, before solving and generating measurement problems.

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