Discovering about symmetry in the wild - plants, flowers and animals - is a lot more engaging than learning the rules in a classroom, and offers children the chance to make their own observations and conclusions. Symmetry is an important maths skill; children should be able to list lines of symmetry as a characteristic of many shapes alongside other attributes such as edges and sides. Think square (4 lines), rectangle (2 lines), equilateral triangle (3 lines), and circle (infinite lines!).
To pique their curiosity into exploring the rules of symmetry, we’ve come up with a very simple craft you can do at home, and then some top tips for discovering a little more.
1 Grab a piece of A5 card. If you’ve got an old toucanBox to hand, the front panel is the perfect size.
2 Fold the card in half, so it bends down the middle.
3 Print out one of the butterfly templates, or draw your own! On a piece of A5 paper, draw half a butterfly - half of its body, and just one wing. Colour it in!
4 Glue the butterfly to the right side of the cardboard.
5 Cut out a piece of foil to fit the other side of the cardboard. Glue it down, shiny side up.
6 Flutter the butterfly’s wings to reveal the whole butterfly. It’s perfectly symmetrical!
As with our very snazzy cardboard butterfly, using a mirror to detect lines of symmetry is effective, and offers a nice level of trial and error for children. After just a few simple rules children should be able to detect whether a shape, picture or item has any lines of symmetry. They just need to make sure they’re placing the mirror down the centre of the object, and looking in the mirror to see if the shape is recreated perfectly. After that, get experimenting!
Another great way to count the lines of symmetry in shapes is to use paper! Just cut out a bunch of shapes - a square, rectangle, triangle, trapezium, hexagons and some irregular polygons - and practice folding them down the centre. If they fold in half perfectly, you’ve discovered a line of symmetry! If it doesn’t fold perfectly (i.e. you can see bits of the shape poking out from your fold) that’s not a line of symmetry. Afterwards you can flatten the shape back out and count the creases to work out how many lines of symmetry you’ve discovered.
Once you’ve mastered finding symmetry in shapes using a mirror, grab a camera and get exploring outside. The aim of the game is to see if you can see a line of symmetry just by looking at the object, and then test it to see if your assumption was correct. Have a look at flowers and fallen leaves. Observe different animals; perhaps you can spot a butterfly or the stripes on a cat. Have a look at really large objects; notice how the branches of a tree stretch out. Are they symmetrical?
Once you’ve made your observations, it’s time to test. Take a picture of each object. With smaller items like fallen leaves or stones, you could take them back with you. Use a mirror to test your symmetry assumptions. Were you correct? Are there more lines of symmetry than you initially noticed?