The concept of zero is surprisingly deep, and it took human thinkers quite a long time to come up with the notion of zero. Before mathematicians understood the notion of zero, there was much ambiguity about written numbers. Zero was introduced as a placeholder to avoid these ambiguities. In India, the concepts of 0 as a placeholder and 0 as a number were associated with one another much earlier than in Babylon. It is from the Indians that we get our present-day symbol for 0.
Place value is very interesting to think about.
Believe it or not, place value is a relatively new notion in mathematics. It took humans 28,000 years to come up with the notion of place value. Before the place value system was invented, symbols had to be repeated to express the right amount. Their place value system was different from the one we use today because it was base 60 rather than base 10. However, as time passed, ideas evolved, and by 500 A.D., Indians had invented a base 10 system that had unique symbols for the numbers 1 through 9, employed a place value notation, and used a zero.