Section overview
- Reading Whole Numbers
- Writing Whole Numbers
Because our number system is a positional number system, reading and writing whole numbers is quite simple.
Reading whole numbers
To convert a number that is formed by digits into a verbal phrase, use the following method:
- Beginning at the right and working right to left, separate the number into distinct periods by inserting commas every three digits.
- Beginning at the left, read each period individually, saying the period name.
Sample set a
Write the following numbers as words.
Read 42958.
- Beginning at the right, we can separate this number into distinct periods by inserting a comma between the 2 and 9.
42,958 - Beginning at the left, we read each period individually:
Forty-two thousand, nine hundred fifty-eight.
Read 307991343.
- Beginning at the right, we can separate this number into distinct periods by placing commas between the 1 and 3 and the 7 and 9.
307,991,343 - Beginning at the left, we read each period individually.
Three hundred seven million, nine hundred ninety-one thousand, three hundred forty-three.
Read 36000000000001.
- Beginning at the right, we can separate this number into distinct periods by placing commas. 36,000,000,001
- Beginning at the left, we read each period individually.
Thirty-six trillion, one.
Practice set a
Write each number in words.
101,074,003
One hundred one million, seventy-four thousand, three
Writing whole numbers
To express a number in digits that is expressed in words, use the following method:
- Notice first that a number expressed as a verbal phrase will have its periods set off by commas.
- Starting at the beginning of the phrase, write each period of numbers individually.
- Using commas to separate periods, combine the periods to form one number.
Sample set b
Write each number using digits.
Seven thousand, ninety-two.
Using the comma as a period separator, we have
7,092
Fifty billion, one million, two hundred thousand, fourteen.
Using the commas as period separators, we have
50,001,200,014
Ten million, five hundred twelve.
The comma sets off the periods. We notice that there is no thousands period. We'll have to insert this ourselves.
10,000,512
Practice set b
Express each number using digits.
Twenty trillion, three billion, eighty million, one hundred nine thousand, four hundred two.
20,003,080,109,402
Exercises
For the following problems, write all numbers in words.
437,105
four hundred thirty-seven thousand, one hundred five