In this assessment task from Bowland, students are provided with a page containing circles and triangles which represent different trees in a wood. Students are tasked with estimating how many of the different types of trees there are and then required to simplify a complex situation and choose an appropriate method to use to count the trees. Students are encouraged to use a method of sampling and relative proportions in order to estimate the number of trees. They then consider the validity of their results and are asked to communicate their method and reasoning clearly. Teacher guidance includes concepts which may be discussed with students, examples of probing questions which may be useful and assumptions that students need to make when completing the task. The assessment guidance consists of a progression table detailing how students may improve in each of the key processes. The resource concludes with a number of examples of students' work, together with comments, probing questions and feedback.