As this is the last week before half term, I thought we should do some shape work. However please use ttrockstars and the Topmarks hit the button games to practise number skills for 5 minutes every day.
Use the BBC video to remind yourselves what symmetry is. https://www.bbc.co.uk/bitesize/topics/zrhp34j/articles/z8t72p3
Now try these - the second sheet is quite tricky!
It doesn't matter if you don't see all the lines of symmetry - you are training your brain to spot them. Humans have evolved brains that see lines of symmetry that run from top to bottom. Apparently, it's to do with recognising faces, and the more symmetrical the face, the more other people think it's good looking. Remember, no one has a perfectly symmetrical face, and if you are spotted using a mirror a mirror to check how good looking you are people will think you are vain.
This leads to the subject of Things No One Tells You You Can Do To Make Tests Easier. IT HELPS TO ROTATE THE PAPER. Seriously, because we see symmetry more easily when the line of symmetry runs from top to bottom, twisting the paper and rotating it is sensible (and within The Rules).
This is all about identifying acute angels, right angles and obtuse angels. Reflex angels are mentioned but strictly speaking they can be left until Y4. We use the pun on 'cute' being small to help.
A polygon is a 2D shape which only has straight lines. Or it's what you shout if your parrot flies out of the window.
So circles, ovals, semi circles etc are not polygons - they are just 2D shapes and we'll leave them for another day. Children need to know the names of the polygons and the difference between regular and irregular polygons.
No sheets today - but can the children design a poster to identify different polygons?
Regular Polygon symmetry
Children need the experience of looking for symmetry. When they understand it, it's easy. I set this last year, thinking that there was some rich mathematical thinking to stretch some of the children. I ended up tearing my hair out because finding all the lines of symmetry for each shape proved to be harder than I expected.
If you child spots all of them, there are a few things they might notice. For a regular polygon, the number of lines of symmetry matches the number of sides. All lines of symmetry cross in the centre of the shape. And if the number of sides is odd or even, this affects where the lines of symmetry begin and end.