I tried an activity game with my 4y old son for measuring objects in his room using blocks to learn relative sizes. However, he soon got bored by it. Noe that he has an interest in animals and he has a small collection of animals gifted by his grandma, we decided to do the measuring up game again.
After watching a couple of videos on youtube to know that this is something zoo keepers and vets do in real life, the engagement and interest spiked.
We borrowed the Stichting tape and kitchen scale, measured up the animals and filled in our little zoo book by noting the measurements against the animal name copied from a textbook.