TL;DR
In order to become a master of testing data sets, you must be able to explain to any person in the world, how is test data stored and manipulated in the computer. We will start with decimal data. The post is aligned with the Black Box Software Testing Foundations course (BBST) designed by Rebecca Fiedler, Cem Kaner, and James Bach.
When you agree with your boss your payment compensation, that payment value is encoded using decimal number digits:
1, 2, 3, 4, 5, 6, 7, 8, 9, 0
We have ten fingers on our hands. So first counting was using our fingers. Decimal refers to 10. All decimal numbers are represented using base 10 arithmetic where every decimal number is represented as the sum of powers of 10.
We start with special case, 1:
And here is how we represent a decimal number with boxes approach: