How to cut onions?

So I find my self preparing tea this evening.It is spaghetti bolognaise. As I start to chop the onion I am mindful of my daughters lesson of how to cut onions a few days earlier.
'Mum', she said' ' you must never cut the bottom off the onion first, that bit is last, so the onion doesn't fall apart as you chop!!'
And so I find myself upstaged by my daughter and also finding the official 'school' way of cutting an onion a challenge.
I then realise that no one has ever shown me how to cut an onion until now. I made things like lemon curd and swiss roll (fat free you know!) at school.
So I have been blissfully unaware that there is an official way to chop!! But now I know.... I shall carry on my way anyway!!