Notes

A number can be written in three different ways: standard form (using digits), expanded form (as an addition statement), or word form (using words). Here are some tips for writing a number in word form.

Just as in standard form, each period is separated by a comma.
The word and is not used to write whole numbers in word form.
A hyphen is used in two word numbers between 20 and 100. For example, 99 is written as ninety-nine.
Zero acts only as a placeholder, so it does not need to be written.
Example:
Reminder:
The word and is not used when writing out whole numbers.
Express the number 846,120,050 in word form and expanded form.

Solution:
Word form: Eight hundred forty-six million, one hundred twenty thousand, fifty

Expanded form:
800
,
000
,
000
+
40
,
000
,
000
+
6
,
000
,
000
+
100
,
000
+
20
,
000
+
50
​

Example:
Be Careful!
Even though there were no digits to write in the millions period, we had to write zeroes in as placeholders. Otherwise, the other digits wouldn't have been in the right places.
Write the number seventy billion, two hundred thirty-seven thousand, six hundred two in standard form and expanded form.

Solution:
Standard form: 70,000,237,602

Expanded form:
70
,
000
,
000
,
000
+
200
,
000
+
30
,
000
+
7
,
000
+
600
+
2
​

One thing to notice about place value is that as you move from right to left through a number, the value of each digit gets larger. In fact, as you move left, each position is worth ten times more than the position to the right of it. For example, look at the number 888.

Standard form: 888
Word form: eight hundred eighty-eight
Expanded form:
800
+
80
+
8
​

Even though the digits are all 8s, they each are worth something different. An 8 in the ones place is only worth 8. But, in the tens place, the 8 is worth ten times more than the 8 to the right of it, which is 80. And, moving further to the left, an 8 in the hundreds place is worth ten times more than 80, which is 800.