Outdoor Learning

Primary 5 have been outside calculating the age of the trees in the playground. They were surprised to discover that many of the trees were over 70 years old. They used a mathematical formula to calculate the age of each tree. 
Step 1 Measure 1m from the ground against the tree trunk using a metre stick.
Step 2 Then, measure the circumference of the trunk (measuring to the nearest cm!)
Step 3 Divide the circumference by 2.5 
 Roughly, every 2.5cm of the circumference of the tree represents about one year’s growth.

  So to estimate the age of a living tree, divide the circumference by 2.5.

  For example a tree with a circumference of 40cm will be sixteen years old.

  40cm ÷ 2.5 = 16 years old.

Try it in your garden!