Lesson 1

Whole Number Place Value

Reading & Writing Whole Numbers

Addition

Digits & Place Value

1 2 3 , 4 5 6 , 7 8 9 . 1 2 3 4 5

hundred millions

ten millions

millions

hundred thousands

ten thousands

thousands

hundredstens

ones

tenths

hundredths

thousandths

ten thousandthshundred thousanths

Example 1.1

• In the number 46,235:

• what is the value of the digit 5?

• what is the value of the digit 2?

• what is the value of the digit 4?

Reading & Writing Whole Numbers

• all numbers between 20 and 100 that do not end in zero are hyphenated words when we write them out:

• 23: twenty-three

• 51: fifty-one

Reading & Writing Whole Numbers

• the word “and” is not used

• 501: five hundred one

not five hundred and one

• 422: four hundred twenty-two

not four hundred and twenty-two

Example 1.2

• Use words to write this number:

51,723,642

Example 1.3

• Use digits to write the number:

• fifty-one billion, twenty-seven thousand, five hundred twenty

Expanded Form

• To write a number in expanded form:

• write each of its nonzero digits multiplied by the place value of the digit

• use parenthesis to enclose each of these multiplications

• put a plus sign between each set of parenthesis

Example 1.4

• Write the following number in standard form:

(5 x 1000) + (2 x 10)

Example 1.5

• Write the following number in expanded form:

6,305,126

Addition

• addend: each number we’re adding

• sum: answer of addition problem

• to add whole numbers, we line up the numbers so that the last digits are aligned vertically

Example 1.6

• Add: 4 + 407 + 3526