The Babylonians had simply left a space open when they needed a zero in writing down large numbers. The Egyptians had a symbol for zero (“nfr”), which they used it in bookkeeping to denote “no money,” and in architecture to denote the ground level (the layers of stones of a pyramid were counted in “cubits above nfr”).

The first person to use the zero not just as a placeholder or a symbol for “nothing,” but as a number to be used in calculations was Brahmagupta (c. 598–668). He gave the rules of calculating with zero that we are still familiar with today, such as:

"The product of a negative and a positive is negative, of two negatives positive, and of positives positive; the product of zero and a negative, of zero and a positive, or of two zeros is zero."

Brahmagupta similarly gave rules for calculating with negative numbers.

Somehow, the Greeks had never considered either the zero nor negative numbers. Their focus had been geometry, where numbers corresponded to lengths of lines. Since lines cannot be negative, they never considered negative numbers as viable solutions. Also, Roman numerals dont require a zero in larger numbers (for instance "10" has a zero in it, but in Roman numerals this is simply "X").

The image in the post is the first use of the zero as a placeholder, predating Brahmagupta.

"The Great World History Book"