CONFIDENTIAL 1

Good Afternoon!

Today we will be learning about Estimating, comparing & ordering Of Decimal

numbers.Let’s warm up :

Write the word name for the following:

1) 15.42

2) 8.9

What is the standard form of:

4) Thirty-two hundredths

5) Five hundred ninety-nine thousandths

3) 0.578

1) Fifteen and forty two hundredths

2) Eight and nine tenths

3) Five hundred and seventy eight thousandths

4) 0.32

5) 0.599

CONFIDENTIAL 2

DECIMAL: A number that uses place value and a decimal point to show tenths, hundredths and the thousandths.

0.12 is a decimal number for twelve hundredths.

0.125 is a decimal number for one hundred twenty-five thousandths.

0.1 is a decimal number for one tenth.

DECIMAL POINT: A period separating the ones and the tenths in the decimal is the Decimal Point.

Review

CONFIDENTIAL 3

There are other decimals such as hundredths or thousandths. They all are based on the number ten just like our number

system.

The decimal 0.4 could be pronounced as FOUR TENTHS or as ZERO POINT FOUR .

A decimal may be greater than one. The decimal 3.4 would be pronounced as THREE AND FOUR TENTHS.

The decimal 11.64 could be pronounced as ELEVEN AND SIXTY-FOUR HUNDREDTHS or

as TWELVE POINT SIXTY-FOUR .

Review

CONFIDENTIAL 4

Therefore, there are Three tenths, Six hundredths, Five thousandths, and Seven ten thousandths in the number 0.

3657.

Decimal numbers, such as O.3657, have four digits after the decimal point.  Each digit is a different place value.  

The first digit after the decimal point is called the tenths place value. There are Three tenths in the number O. 3657.

The second digit tells you how many hundredths there are in the number.  The number O. 3657 has Six hundredths. 

The third digit is the thousandths place which is Five thousandths. 

The fourth digit is the ten thousandths place which is Seven ten thousandths in this example. 

Review

CONFIDENTIAL 5

EQUIVALENT DECIMALS: Decimals that name the same numbers and show the same value are Equivalent decimals.

0.4 and 0.40 are Equivalent decimals.

This model shows

the value 0.4

This model shows

the value 0.40

Review

CONFIDENTIAL 6

Write the word name for the decimal “ 0.57 “

ONES TENTHS HUNDREDTHS

0 5 7

.We will name the decimal number by reading the

number and place value of the last digit at the right.

So, the word form of 0.57 is: Fifty Seven Hundredths.

This can also be shown with the help of models.

The portion shaded with green represents the valve 0.57

Review

CONFIDENTIAL 7

If there are two decimal numbers we can compare them.  One number is either greater than, less than or equal to the other number.

When decimals are compared start with tenths place and then hundredths place, etc.

If one decimal has a higher number in the tenths place then it is larger than a decimal with fewer tenths.

If the tenths are equal compare the hundredths, then the thousandths etc. until one decimal is larger or there are no more places to compare.

If each decimal place value is the same then the decimals are equal.

Let’s get started with the Decimal numbers

CONFIDENTIAL 8

We can compare and order decimals by locating them on a number line.

The number on the left is always less than any number to its right.

The ordering of numbers is best shown on a number line.

The value of a number increases as you move to the right along the number line.

To compare two numbers, first locate each number on the number line.

CONFIDENTIAL 9

0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

Compare 3.7 and 3.2

3.4 3.7

Number on the left.

Number on the right.

Hence, 3.2< 3.7

CONFIDENTIAL 10

Understanding of comparing and ordering whole numbers can be smoothly transferred to

comparing and ordering decimal numbers.

We always compare from left to right because the place values on the left are the greatest.

The most important concept for students to remember is that to compare or order numbers, they must first align them by place value.

Then they compare the digits from left to right until they are different.

The number with the greater different digit is the greater of the two numbers.

CONFIDENTIAL 11

Compare 8.65 and 8.8

Align the decimal points by place value.

STEP 1:

8.65

8.8

STEP 2:

Fill in the place value with zeroes.

8.65

8.80

CONFIDENTIAL 12

Compare the digits from left to right until they are different.

STEP 3:

8.65

8.80

Same

Left to right

Different

Since 6<8,

8.65 < 8.8.

CONFIDENTIAL 13

Order 5.49, 5.4, 5.57and 6.03 from Greatest to Least.

Align the decimal points by place value.STEP 1:

5.49

5.40

5.57

6.036>5.So, 6.03 is the greatest decimal.

Fill in the place value with zeroes

STEP 2:Compare the tenths.

5.49

5.40

5.57

Here,5.57 > 5.495.57 > 5.40

CONFIDENTIAL 14

Compare the hundredths.STEP 3:

5.49

5.405.49 > 5.40

The order from greatest to least is 6.03, 5.57, 5.49, 5.4.

CONFIDENTIAL 15

Order 0.43, 0.471 and 0.474 from Least to Greatest.

Compare the hundredths.STEP 1:

STEP 2:Compare the thousandths.

0.430

0.471

0.474

3 < 7.So, 0.430 is the least decimal.

0.471

0.474

1 < 4.So, 0.471 < 0.474.

The order from least to greatest is 0.430, 0.471 , 0.474.

CONFIDENTIAL 16

BREAK

CONFIDENTIAL 17

GAME

Click on the link below for some exciting puzzle

http://http://www.thekidzpage.com/onlinejigsawpuzzles/kids-jigsaw-puzzles/12-piece-jigsaw/12-27-06-piggy.html

CONFIDENTIAL 18

Assignments

Compare. Write >, <, or, =.

1) 4.78 4.68 2) 6.70 6.7

3) 0.652 0.657

4) 6.18 6.67

5) 0.78 0.78 6) 8.9 8.98

1) > 2) =

3) <

5) =

4) <

6) <

CONFIDENTIAL 19

Write in order from greatest to least.

7) 5.78, 4.68, 4.8, 5.44

8) 0.956, 0.868, 0.856, 0.767

7) 5.78, 5.44, 4.8, 4.68

8) 0.956, 0.868, 0.856, 0.767

CONFIDENTIAL 20

Write in order from least to greatest.

9) 0.78, 0.68, 0.8, 0.44

10) 7. 567, 6.45, 7.894, 5.474

9) 0.44, 0.68, 0.78, 0.8

10) 5.474, 6.45, 7.567, 7.894

CONFIDENTIAL 21

Let’s review what we did today.

If there are two decimal numbers we can compare them.  One number is either greater than, less than or equal to the other number.

When decimals are compared start with tenths place and then hundredths place, etc.

If one decimal has a higher number in the tenths place then it is larger than a decimal with fewer tenths.

If the tenths are equal compare the hundredths, then the thousandths etc. until one decimal is larger or there are no more places to compare.

If each decimal place value is the same then the decimals are equal.

The number on the left is always less than any number to its right.

The ordering of numbers is best shown on a number line.

CONFIDENTIAL 22

Compare 8.65 and 8.8

Align the decimal points by place

value.

STEP 1:

8.65

8.8

STEP 2:

Fill in the place value with

zeroes.8.65

8.80

Compare the digits from left to right until they are

different.

STEP 3:

8.65

8.80

Same

Left to right

Different

Since 6<8,

8.65 < 8.8.

CONFIDENTIAL 23

Order 0.43, 0.471 and 0.474 from Least to Greatest.

Compare the hundredths.STEP 1:

STEP 2:Compare the thousandths.

0.430

0.471

0.474

3 < 7.So, 0.430 is the least decimal.

0.471

0.474

1 < 4.So, 0.471 < 0.474.

The order from least to greatest is 0.430, 0.471 , 0.474.

CONFIDENTIAL 24

You have done a nice job.See you in the next session.