Grouping of decimal numbers
Given a lot of 4-digit numbers (0000 to 9999)
- 10^4 = 10000 numbers altogether
Can have 10^1 (10) groups of 10^3 (1000)
Can have 10^2 (100) groups of 10^2 (100)
Can have 10^3 (1000) groups of 10^1 (10)
Can have 10^4 (10000) groups of 1
Any large group can be divided into smaller groups, recursively