Why is it that commas(or decimals) are used to group sets of 3 digits together? Like for a million you usually see; 1,000,000 Why don't we group digits together in groups 4; 100,0000 Or since we use a base 10 numbering system, why not 5 or 10; 10,00000 or 1,0000000000 Is there something magical about the number 3 or is it just used because its easy to count? Why we're on the topic, why do we say 1 million is 1,000,000? Why isn't 1 million 1,000,0000? If you haven't figure it out yet, I'm procrastinating from doing my homework.