Understanding Whole Numbers

Understanding Whole Numbers

Lessons 1-1 to 1-2

standard form – a number is written using digits and place value (the regular way to write numbers).

expanded form – a number is written as a sum using the place and value of each digit.

word form – a number is written in words as you would read it in standard form.

(Example: 53,482)

(Example: fifty thousand + three thousand + four hundred + eighty + two)

(Example: fifty-three thousand, four hundred eighty-two)

Vocabulary Forms

Place Value Chart

How To Read a Large Number

• Numbers are grouped in sets of three (each set is called a period).

• Only read three numbers at a time.

• Say the name of the period that the numbers are in.

• Say “and” for the decimal, but do not say “and” if there isn’t a decimal.

Example

4,658,089Millions period Thousands period Ones period

Four million, six hundred fifty-eight thousand, eighty-nine.

Period family

Thous family

Mills family

Bills family

Whole Number Families

Number Lines

Numbers towards the right on a number line are larger. As you move to the left on a number line, the numbers get smaller.

What’s Bigger? 1 or -2?1 is larger because it is to the right of the -2. What numbers are smaller than -2?

-3 and -4 are both smaller than -2 because they are to the left of -2.

Comparing Numbers

• Line the numbers up vertically (up and down) by the ones place.

• Start at the left and compare the digits.

• Move towards the right until you find a difference.

Just a Reminder…

< means “less than.” (Hint: the point points to the small number)

> means “greater than.” (Hint: the open side points to the larger number)

= means “equal to.”

Example

45,312 45,321

45,312 45,321

1 is less than 2

<

Example 2 – Put the numbers in order from least to greatest.

321; 345; 354; 29; 1,013; 312; 332

1.

2.

3.

4.

5.

6.

7.

32134529

3541013

312332

smallest 29

largest 1,013

312

321

332

345

354

Reading and Writing

DecimalsLesson 1-2

“AND” “ths”

Reading Decimals

Read the number before the decimal point.

Say “AND” when you get to the decimal.

Read the number after the decimal.

Say the name of the place that the decimal ends in.

Place Value With Decimals

Example

8,243.67Eight thousand, two hundred forty-threeand sixty-seven hundredths

Try This: 9,532.41 480. 123

37.06

Expanded Form Write the number that appears before

the decimal. For decimals, place a zero in the ones

place. Also, substitute zeroes for all spaces

after the decimal point that come before the digit that you are working with.

Example: Write 13.361 in expanded form.

Remember, deal with the number before the decimal first.

Then, do the decimal part.

0.060.3 +10 + 3 + + 0.001

Try This:Write 429.715 in expanded form.

Answer:400 + 20 + 9 . 7 + 01 + .005

From Words to Standard Form

Read everything that comes before the word “and.” Write that number down.

Place a decimal point at the word “and.”

Read the last word of the sentence to see how many decimal places you need.

Fill in the decimal places with your number. Fill in as far to the right as possible, and use zeroes to fill any empty spaces.

Example: Write the following number in standard form:

Two hundred six and fifty-four ten-thousandths

206.The word “ten-thousandths” indicates that we need four decimal places.

__ __ __ __5 40 0

When we clean it up, the answer is 206.0054

Classwork Go to this site that will help you Read and Write

Whole Numbers

Whats your Name?

Try this site to read and write Decimals:

Rags To Riches

HOMEWORK

Homework: Textbook pg. 10-12, #2-40 Evenso Bonus 2pts: Stretch Your

Thinking

Commonly Misspelled Numbers:

• hundred

• thousand

• eight

• forty

• ninety