I have heard that in Canada and the United States of America, when we write a decimal number, then we use a period, like 1.111. When we write large numbers, then we use a comma, like 1,111. Sometimes we use spaces for large numbers, like 1 111. I have also heard that Europe, Southern Africa, Central America, the West Indies, and South America use commas and periods the other way around. So, for Americans, 1.111 is the decimal number, while for Europeans, 1.111 is one thousand one hundred eleven. For Americans, 1,111 is one thousand one hundred eleven, while for Europeans, 1,111 is the decimal number. 1 111 is one thousand one hundred eleven for the entire world. How did the commas and periods develop historically?
Update: Recently, USA and China too switchedis also switching to using comma for the decimal. Now "Made In China" products too display the decimal comma.