1. Comparing and Ordering
Decimals
5th Grade Math
Today you will be learning more about number sense.
We will be comparing and ordering decimals.
By: Kellea McGehee

2. The purpose of today’s lesson is to:
Compare decimals
Ex: > 2.04
Order decimals
1.02, 1.25, 1.50 (least to greatest)
1.50, 1.25, 1.02 (greatest to least)
After this lesson, you will be able to compare decimals using the greater than, less than, or equals symbol.
You will also be able to order decimals from least to greatest and greatest to least.
Has anyone done this before?

3. Reviewing Place Values
To the hundredths place!
Hundreds
Tens
Ones
Tenths
Hundredths 7 2 9
Place Value Chart
First we will look at the hundredths pace value .
Notice the difference between hundreds and hundredths.
Hundreds refers to whole numbers and is found on the left side of the decimal point.
Hundredths refers to the numbers located to the right of the decimal point.
How do we say this in words?

4. Decimals to the hundredths place value!
Reading Decimals
Decimals to the hundredths place value!
Again, notice the hundredths place value.
In words, 7.29 is seven and twenty-nine hundredths

5. Reviewing Place Values
To the Thousandths Place!
Hundreds
Tens
Ones
Tenths
Hundredths
Thousandths 6 3 1 7 4
Place Value Chart
Now lets look at the thousandths place value.
Do you understand the difference between thousands and thousandths?
Thousands refers to the whole number value located to the left of the decimal point.
Thousandths refers to the decimal value found to the right of the decimal point.
Notice the difference between hundreds and hundredths.
Hundreds refer to whole numbers and is found on the left side of the decimal point.
Hundredths refers to the numbers located to the right of the decimal point.
Thousands refers to a whole number and is found to the left of the decimal place.
Thousandths refers to a decimal and is found to the right of the decimals point.
How do we say this in words?
Lets take a look…

6. Reading Decimals Decimals to the thousandths place:
When we read or say a decimal number out loud, we represent the values behind the decimal in the exact same way that we do when we write them.
In words, is sixty-three and one hundred seventy-four thousandths.

7. Reading Decimals 2.4 = Two and four tenths 2.04 =
Two and four hundredths
2.004 =
Two and four thousandths
Lets take a minute to practice with several problems.

8. Comparing Decimals
How does this work?

9. Comparing Decimals Step 1: Line up the decimal points
Step 2: Find the first place where the digits differ
Step3: Compare the differing digits
Step 4: Use <, >, or = to state your answer
When we use greater than or less than symbols, here is a hint to help you remember them correctly:
Think of the symbols ( <, >) as an alligator’s mouth. Alligators are hungry and like to eat a lot.
So, the alligators open mouth is always facing the bigger number.

10. How do we compare decimals:
Comparing Decimals
How do we compare decimals:
Example :
Line up the decimal points
68.563
Starting at the left, find the first place the digits differ
Compare the digits
3 > 0
Since 3 > 0
(three is greater than zero)
>
Lets look at these steps in more detail

11. Comparing Decimals: Practice
Use >, <, or = to compare each pair of decimals.
Practice:
Answer:
4.08 >
Practice:
Answer:
<
Lets try some practice.

12. Ordering Decimals How do we go from least to greatest?
How do we go from greatest to least?
Remember, once you learn how to go from least to greatest, you should also be able to determine greatest to least very easily.
New Visions Technology Inc.

13. Line up the decimal points
Ordering Decimals
How do we order decimals:
Step 1
Step 2
Step 3
Line up the decimal points
Annex zeros so that each has the same number of decimal places.
Use place value to compare and order the decimals.
What does this mean?

14. Line up the decimal points
Ordering Decimals
From Least to Greatest
Step 1
Step 2
Step 3
Line up the decimal points
Annex zeros so that each has the same number of decimal places.
Use place value to compare and order the decimals.
Example
4.073
4.73
4.0073 4
4.0730
4.7300
4.0000
4.000
Lets look at these steps in going from least to greatest.
Do you know what it means to annex the zeros?
This means to add zeros so that each value has the same number of decimal places.
Notice the underlined zeros. These were the zeros we added so that each number would have the same number of decimal places.
This will help us to see what order the decimals should be in.

15. Line up the decimal points
Ordering Decimals
From Greatest to Least
Step 1
Step 2
Step 3
Line up the decimal points
Annex zeros so that each has the same number of decimal places.
Use place value to compare and order the decimals.
Example
3.074
3.73
3.0073 3
3.0740
3.7300
3.0000
Now we will compare decimals going form greatest to least.

16. Ordering Decimals: Practice
Order from Least to Greatest:
3.01, 3.009, 3.09,
Answer , 3.009, 3.01, 3.09
Order from Greatest to Least:
45.303, , 45.03,
Lets try some problems.
Raise your hand when you think that you have the answer.
Answer , , 45.03,

17. Review: Comparing Decimals
Step 1: Line up the decimal points
Step 2: Find the first place where the digits differ
Step3: Compare the differing digits
Step 4: Use <, >, or = to state your answer
Here is our review. Remember the differences between numbers that appear before and after the decimals. Can anyone tell me what those differences are?

18. Review: Ordering Decimals
New Visions Technology Inc.
Step 1
Step 2
Step 3
Line up the decimal points
Annex zeros so that each has the same number of decimal places.
Use place value to compare and order the decimals.
Now we’ll review how to order decimals. Remember what it means to annex the zeros. Can someone tell me what this means?
How does it help us when organizing fractions?

19. How often do you feel you use good number sense?
Always
Sometimes
Never 2 3

20. Practice Links Comparing Decimals Homeschoolmath.Net
Ordering Decimals-MATHSCORE.COM
Take the time to practice using the links provided above.
Mathscore provides answers too.

21. Image References Cool Math: Place Values for Decimals MathTeacher.com
HelpingwithMath.com
Google Images