Our challenge was to find and calculate how old the oldest tree is in the Orchard. first, we measured 1m from the ground against the tree trunk using a meter stick. Then we measured the circumference of the trunk (measuring to the nearest cm!). We recorded our results accurately using a table. 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, we divided 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. The oldest tree that we could measure in the Orchard is 54 years old!