Transcript Document

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
3) 0.578
What is the standard form of:
4) Thirty-two hundredths
5) Five hundred ninety-nine thousandths
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Review
DECIMAL: A number that uses place value and a decimal point to show
tenths, hundredths and the thousandths.
 0.1 is a decimal number for one tenth.
 0.12 is a decimal number for twelve hundredths.
 0.125 is a decimal number for one hundred twenty-five thousandths.
DECIMAL POINT: A period separating the ones and the tenths in the
decimal is the Decimal Point.
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Review
The decimal 0.4 could be pronounced as FOUR TENTHS or
as ZERO POINT FOUR .
There are other decimals such as hundredths or thousandths. They all
are based on the number ten just like our number system.
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 .
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Review
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.
Therefore, there are Three tenths, Six hundredths, Five
thousandths, and Seven ten thousandths in the number 0. 3657.
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Review
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
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Review
Write the word name for the decimal “ 0.57 “
ONES
0
.
TENTHS
HUNDREDTHS
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
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Let’s get started with the Decimal numbers
 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.
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We can compare and order decimals by locating them on a number line.
 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.
 The number on the left is always less than any number to its right.
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Compare 3.7 and 3.2
Number
on the
right.
Number
on the
left.
3.7
3.2
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
Hence, 3.2< 3.7
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Understanding of comparing and ordering whole
numbers can be smoothly transferred to comparing
and ordering decimal numbers.
 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.
 We always compare from left to right because the place values on
the left are the greatest.
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Compare 8.65 and 8.8
STEP 1:
Align the decimal points by place value.
8.65
8.8
STEP 2:
Fill in the place value with zeroes.
8.65
8.80
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STEP 3:
Compare the digits from left to right until they are different.
Different
Same
8.65
8.80
Since 6<8,
8.65 < 8.8.
Left to
right
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Order 5.49, 5.4, 5.57and 6.03 from
Greatest to Least.
STEP 1:
Align the decimal points by place value.
5.49
5.40
5.57
Fill in the
place value
with zeroes
6>5.
So, 6.03 is the greatest decimal.
6.03
STEP 2:
Compare the tenths.
5.49
5.40
5.57
Here,
5.57 > 5.49
5.57 > 5.40
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STEP 3:
Compare the hundredths.
5.49
5.40
5.49 > 5.40
The order from greatest to least is 6.03, 5.57, 5.49, 5.4.
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Order 0.43, 0.471 and 0.474 from
Least to Greatest.
STEP 1:
Compare the hundredths.
0.430
0.471
0.474
STEP 2:
3 < 7.
So, 0.430 is the least decimal.
Compare the thousandths.
0.471
0.474
1 < 4.
So, 0.471 < 0.474.
The order from least to greatest is 0.430, 0.471 , 0.474.
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BREAK
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GAME
Click on the link below for some exciting puzzle
http://www.thekidzpage.com/onlinejigsawpuzzles/kids-jigsawpuzzles/12-piece-jigsaw/12-27-06-piggy.html
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Assignments
Compare. Write >, <, or, =.
1) 4.78
3) 0.652
5) 0.78
4.68
0.657
0.78
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2) 6.70
6.7
4) 6.18
6.67
6) 8.9
8.98
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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
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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
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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 ordering of numbers is best shown on a number line.
 The number on the left is always less than any number to its right.
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Compare 8.65 and 8.8
STEP 1:
Align the decimal
points by place value.
8.65
8.8
STEP 3:
Compare the digits from left to
right until they are different.
STEP 2:
Fill in the place
value with zeroes.
Same
8.80
8.65
8.80
8.65
Left to
right
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Different
Since 6<8,
8.65 < 8.8.
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Order 0.43, 0.471 and 0.474 from
Least to Greatest.
STEP 1:
Compare the hundredths.
0.430
0.471
0.474
STEP 2:
3 < 7.
So, 0.430 is the least decimal.
Compare the thousandths.
0.471
0.474
1 < 4.
So, 0.471 < 0.474.
The order from least to greatest is 0.430, 0.471 , 0.474.
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You have done a nice job.
See you in the next session.
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