I like the concept, but if I may editorialize, I feel the phrasing needs work. "The smallest number you can't count to" is a negative statement, which makes it confusing right off the bat.
What do you mean, a number I can't count to? If I'm 8 years old this is like throwing a null pointer exception in my brain.
What do you mean, a number I can't count to? If I'm 8 years old this is like throwing a null pointer exception in my brain.