Understanding Whole Numbers Lessons 1-1 to 1-2
Feb 24, 2016
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