The other day, DD1 and her cousin were beaming with energy, running around and trying to pick various things that they eyed upon. One such thing was this shampoo sachets roll. I gave an idea of counting the sachets, folding the roll to half, count again and repeat.
Then, bunch of ideas followed, all of them being directed by the two young kids.
One was, fold the two sachets at both ends, count, repeat. And this is what is called subtraction in formal school or reverse step counting.
There are many ways of learning. It can happen even using the very simple items that we see everyday.