What is the highest number there is? Let's try and find out by working our way up. To save myself from having to write down a lot of digits, let me first explain the scientific notation:

- 1 × 10
^{2}= 1 × 10 × 10 = 100 - 1 × 10
^{3}= 1 × 10 × 10 × 10 = 1000 - 1 × 10
^{4}= 1 × 10 × 10 × 10 × 10 = 10000

*million*, a

*billion*, a

*trillion*, a

*quadrillion*... These can be written respectively as 10

^{6}, 10

^{9}, 10

^{12}and 10

^{15}. You might knew these first few, but that list actually goes on for a while. Take for example a

*vigintillion*, which is 10

^{63}. Are there any higher?

Of course! How about the

*googol*? It is notated as 10

^{100}. That's a ‘1’ with a hundred zeros! Is this the largest number? Nah, we can put at least the

*centillion*(10

^{303}),

*septuagintacentillion*(10

^{513}) and the

*millinillion*(10

^{3003}) on the table.

We need to do better than this, so let's push it into crazy territory. A

*googolplex*is 10

^{googol}— yes, that's 10 to the power of a googol. A ‘1’ with a googol zeros. 10

^{10100}. Fine! It is a 1 with 10 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 zeros. So as you can see I just wrote out a googol. I cannot write out a googolplex: there is not enough room in our universe to do so. See, the number of atoms in the observable universe is estimated to be around 10

^{80}. This means that writing down a googolplex requires far more zeros than there are atoms in the universe!