Lesson plan: Learning with Leaves

Divide the class into teams and ask them to predict whether all leaves are the same shape and size. They could discuss this in pairs. Once you have gathered the collective wisdom of the class you could write it on the board to refer to when you get back. 

Then head outside and ask each team to collect a number of leaves. Depending on where you are working it’s worth laying down some fairly strict rules about picking live leaves off plants. Once people have picked a handful, challenge them to find two identical leaves; it’s best to mention this after they have selected their leaves. 

Ask for feedback as to what methods they used to identify the differences between leaves and check if they have found two the same. It still amazes us that every leaf we have ever seen is unique.

Collect a variety of leaves; again, being strict about respecting live plants is a good idea. You could gently introduce the idea of a fair test by asking pupils about their collecting methods; do they just pick big leaves, easy to measure leaves, pretty ones, etc?

This exercise can be made as complicated or as simple as you like by choosing how open or closed your initial instructions are and by the range of resources you give each group. Here are two suggestions:

1. Show the class all the methods and give each group access to all the equipment and ask them to choose which method they like best.  
2. Each group is given the right equipment and a set of instructions for their specific method of measuring leaves. 

Ultimately their method needs to be consistent. As long as each team measure the same part of each leaf in the same way every time, they will be carrying out a fair test. 

Each team should be asked to make estimates and then make their measurements. Here's how to measure different parts of a leaf: 

Perimeter: You will need string and a ruler. 

1. Place your leaf on a flat surface. 
2. Run the string around the edge of the leaf making sure It follows the shape accurately. This will be fiddly, so make sure everyone has a go and that the team help each other out. 
3. Measure the length of string that has been run around the edge of the leaf. 
4. Record your results neatly.  

Area: You will need squared paper. 

1. Place your leaf on the squared paper. 
2. Draw around the edge of the leaf. 
3. Count the complete squares inside the leaf shape and record them. 
4. Are you going to count the fractions of squares covered. If so, how? 

Length or width: You will need a ruler and notepaper. 

1. Lay your leaf on a flat surface. 
2. Choose what you are going to record and take the same measurement with every leaf. 
3. Write your results down on a piece of paper. You might want to draw a table to make it neater. 

(Make sure this group always measures the same dimension.)

Ask students to write down three reasons why they think their method is the best way of measuring a leaf. Challenge each team to explain their method to another team. 

Doing large scale graphs or histograms on the floor or in the playground is always a firm favourite, the axes can be drawn with chalk or made with string, canes etc. 

Pupils can contribute by labelling the axes, adding their leaves and coming up with a title. If you do it outside wind will be your greatest enemy so be prepared and plan for it. Alternatively, there are any number of opportunities to creatively display your leaf maths in the classroom. 

Ask the pupils to discuss what they have learnt using their mathematical skills. Each team could come up with some rules about the leaves they studied.