Powers of 10 are a useful mathematical tool to comprehend the scale of our Universe.

The smallest measure of length with any meaning is the Plank’s length 0.00000000000000000000000000000000001 m.

Using powers of 10, we can also write this as 1 × 10 ^{-35} m or simply 10 ^{-35}m. 10 is called the base number and 35 is called the ‘exponent’
On the larger end of the scale is the co-moving size of observable space itself, 100,000,000,000,000,000,000,000,000 m. We can write this as 1 × 10 ^{26} m.
We can represent any number using powers of 10 or orders of magnitude. Scientists prefer this scientific notation to write down values of numbers. For example 4500 m can be written as 4.5 × 10 ^{3} m and 0.045 can be written as 45 x 10 ^{-3}.

This game is based on Wikipedia’s article on ‘Orders of magnitude (length)’.