Writing numbers in words are done in different ways based on different standards in different parts of the world but there is a system which can be considered international. Here are a few rules regarding writing numbers in words:

When you write a number in digits, you use commas to separate each three place values starting from far right. Every three digits will in this way be separated using a comma. For example, instead of writing 3236523657, you write your number as follows:

- 3,236,523,657

When you write the number in words, you have to write the commas exactly where the comma is used in the number. For example, the number 23,657 is written as, “twenty-three thousand, six hundred fifty-seven.” Please note that the comma used in the word form of the number was not a part of how I would normally write an English sentence. The comma is an integral part of the number.

When writing numbers below hundred in words, you have to hyphenate the two words. For example, the number 65 is written as “sixty-five” and not as “sixty five.”

Now let’s write some numbers in words for some practice.

- 20,000 is written as, Twenty thousand.
- 36,000 is written as, Thirty-six thousand.
- 36,200 is written as, Thirty-six thousand, two hundred.
- 47,457 is written as, forty-seven thousand, four hundred fifty-seven. (please note that when we read numbers in speech, we usually add the word “and” sometimes between the words which is not required when you write the numbers in words.)
- 30,003 is written as Thirty thousand, three.

In order to be able to write larger numbers, you need to know the name of those place values. Here’s an overview of the place values and the suffixes that are used in conjunction with them.

- 100 trillion, 10 trillion, 1 trillion,, 100 billion, 10 billion, 1 billion,, 100 million, 10 million, 1 million,, 100 thousand, 10 thousand, 1 thousand,, hundreds, tens, ones
- trillion,, billion,, million,, thousand,, none

In (1), I have written the name of each place value. In (2), I have written, the suffix that you have to use in order to write the number in words. Each of those suffixes like “billion,” is related to three place values in a number.

For example, in the number 23,456,789, you would need to use two suffixes, “thousand” and “billion” because your number has eight digits. The first three digits have no suffix. The next three digits use the suffix, “thousand,” and the next three digits, moving towards the left, use the suffix, “million.” So to write the number in words, you would simply write,

- Twenty-three million, four hundred fifty-six thousand, seven hundred eighty-nine.

This way of writing numbers, separating place values in groups of three, starting from the far right is used in the international numbering system. You might come across other terms or phrases to refer to the same concept.

There is another numbering system that is mainly used in some Asian countries like Indian, Pakistan, Afghanistan, etc. That number system is still a decimal (base-10) number system but there are some differences as to how the numbers are called. For example, in the international number system, the number, “100,000” is read or written as, “one hundred thousand.” The same number in the Indian number system is written in digits and in words differently. In digits, it would be written as, “1,00,000” and in words, as, “One Lakh.” In the next article, we’ll talk about the Indian number system.

These articles are used by the author in a series of mathematics courses that will teach you mathematics from the sixth standard all the way up to 12th standard. The purpose of these courses are to help us understand mathematics so that you can use them professionally well. There is a road map that we have put together about the all the courses included, where to starts, etc. To know more about that and have access to those courses, please visit mathematics page on Great IT Courses. Thank you.