Difficult questions

While hanging out my second load of washing, Isabelle asked me:

"What is the biggest number?"

A good question indeed! I gave a simple answer, along the lines of:

"It's called infinity - bigger than you or I could even imagine". Isabelle's response was:

"What is the biggest number?".

Obviously the first answer didn't do the trick! I thought along a different tack.

"What is the biggest number you can think of?"
"It has a two, and an "o" ".
"Well, imagine that number plus one - then plus two, then plus three - and we can go on and on until infinity".

Silence. Then:

"But it has a two, and an "o" ".

I just turned to her now and asked her what she thought the biggest number was, and she said (drawing in the air with her finger):

"It has a two and a zero, and then you can put a two and a zero on your blog to remind people".

So here they are:

2 0