Numbers go on forever.
for grown-ups
What we actually know
Yes. There is no biggest number. Whatever number anyone names, you can add one and get a bigger one, so the counting numbers never run out. You don't need a record or an expert to know this: anyone can check it in their head. That's what makes this round different. The strongest where-from here is working it out.
A googol is a one followed by a hundred zeros. The name was picked by a young boy, Milton Sirotta, when his uncle, the mathematician Edward Kasner, asked him for one. A googol and one is bigger still.
Infinity often comes up. It isn't a number you reach by counting. It's a name for "it never stops". (Mathematicians do use infinity in careful ways, including infinities of different sizes. The round leaves that out.)
The round's real subject is being sure for a good reason. Many rounds end with Kea moving away from a claim. In this one the evidence points toward agree, and a child who stands on really agree is standing there for a reason they can check.
Sources: NRICH (University of Cambridge), "All About Infinity", on why there is no largest counting number (nrich.maths.org/2756); Edward Kasner and James Newman, "Mathematics and the Imagination" (1940), where the googol was first published. You may read different ages for Milton Sirotta (eight or nine) and different years for when he named it, so the round says only "a boy picked the name, a long time ago".
What kids usually bring
- "You can always add one more." The whole idea, in a child's words. The round asks them to try it.
- "Infinity is the biggest number." Very common, and a clever mix-up. The round says people who study numbers call infinity a name for never stopping, not a number you count up to.
- "A googol is the biggest number." Kea's reason. A googol is enormous, and a googol and one is bigger.
- "Everything has to end somewhere." True of most things a child knows: days, books, journeys. The round asks whether counting ends because the numbers stop, or because the counter gets tired.
The round also asks your child to try it: say the biggest number they know, then add one. Whatever they report is welcome. Getting stuck is fine. Trying it is the point.
At dinner
Play "one more" together: take turns saying the biggest number you can think of. The next person adds one. Can anyone win?
Ask: "Is there a number nobody could ever add one to? How do you know?"
Then the one rule: say their reason back before you give yours.
The round never tells your child what to think. This card tells you what we know, so you're never caught out. If your child wants to argue with it, that is the point.
