During one of her conversations with her cousin(I can't recall the context), both of them exchanged some number terms saying, one, five, ten, hundred, thousand, million and it stopped there.
DD1 recalled it some days later and asked me how many zeroes are present in a million.
I usually do not answer right away for any of her question, I started writing 1 followed by zeroes starting with 1 zero, then 2 etc...We read through some maths to see the terms of those big numbers where 1 is followed by 24 zeroes or 27 zeroes...She intently read through that passage (it was on quora) where some numbers were mentioned along with the terms. She asked me how some would read out and we explored together.
Did she memorise the terms of those numbers? No
So, did all that she read just go out of her thoughts? NO!
End of the day, during her dinner, she was recalling those number names and asked me which number had 24 zeroes. We came back to our board and explored more.
That's how learning is when it is lead by a child.