One thing I've struggled with as the father of three children of different ages is teaching our boys the difference between equal and fair.
For example, only one our boys has homework to do each night from school so the amount of homework the boys each do is not equal; is that fair?
Sometimes the kids get different treats or different time spent with them depending on various factors including their needs and ages. This isn't equal; is it fair?
This also applies to non-parenting things: kitty and I share a small bag of chips: even though she is much smaller than me, do I split the bag of chips equally between us: is this fair?
Only recently did I truly understand that equal often seems fair but is often not fair. Just like unequal can seem unfair, but it's often fair.
For example, some organisations allow their employees to fly premium economy on long-haul flights only if they're over 190cm tall – is this equal? Definitely not. Fair? Probably – since if you're that tall regular economy seats on long haul flights are pretty painful for your legs.
I recently used the diagram from the Interaction Institute for Social Change Artist Angus Maguir to explain this to our oldest child:
The diagram uses the terms equality vs equity but I prefer equality vs fairness as I find it easier to use equal and fair, vs equal and equitable – especially with young children. I have found by simply looking at a situation and asking separate questions of whether it's equal and whether it's fair means it's easier to separate the two.