I provided Caleb with plenty of keys and told him to open the lock.
He tried using a big key first.
CALEB: It’s not fit. (Meaning: It doesn’t fit)
ME: Oh no! Why not?
CALEB: It’s too big!
ME: Try another one.
He found the set of small keys and tried it on the lock.
Great workout for those little fingers!
There were three small keys in the set.
After trying them one by one, he was able to open the lock.
Happy face of success!
Lock and Keys
Domestic Goddess Tonni 
Nice one Caleb!!! 🙂