It was snowing leaves in the park earlier today; great flurries of reds, golds, yellows and greens, as the first winds of autumn started to bite and one of our most magical seasons got well and truly underway.
Best whisper it, but leaves are great at adding a bit of autumnal fun to maths too. So with October half term upon us, why not pull on some wellies and a warm coat and set off with the children on a woodland treasure hunt – with a mathematical twist at the end.
You’ll also need to take some squared paper and pencils, as well as a ruler, some tape or other sticky stuff, and a few short pieces of string.
First you need to collect some leaves, either by simply picking them up as you wander along or by finding a good spot and then letting the kids have a free for all. Make sure they get a good random collection, though.
Get them to sort the leaves into colours – there should be a mixture of browns, reds, yellows, and the odd green too. Next, start counting, making a note of how many of each colour they’ve found. Once they’ve got their data, it’s time to plot the number of leaves of each colour on a simple graph. Or, if it’s not too windy, why not create a ‘living graph’ on the ground using sticks as the axes and the leaves they’ve actually collected, or even take the whole lot home and create a masterpiece for the kitchen wall?
You can also use leaves to help learn about perimeters and area too. Ask the kids to pick one leaf each and have a rough guess about how many centimetres they think it is round the edge, or how many square centimetres the whole leaf takes up.
Put the leaf on a piece of squared paper, carefully sticking down the stem to hold it in place, and then draw round the outline. Lift the leaf away and take one of the pieces of string and use it to trace around the leaf’s outline. Keeping your thumb and forefinger as a marker, lift the string away and measure it with the ruler to find the leaf’s perimeter. Who came closest with their guess?
Try it with different sized leaves – how big is the difference between a long thin leaf and a short fat one?
Now, using the outline of the leaf they’ve already drawn, see if they can work out how to find its area. First explain to them what size each square represents; then they’ll need to count up all the full squares and estimate how many extra ‘whole’ squares are made up by all the little fiddly bits round the edge. Add them all together and all of a sudden they know the area of a very random shape, and something which is a million miles away from the straight-edged squares and triangles they’ve drawn in class.
Of course, it’s not just leaves you’ll find on the forest floor at this time of year. Nuts, conkers and acorns will all have plummeted from the canopy and they’re all excellent for playing simple counting games – and so much more fun than using a boring pen and paper!