Upload
lee-doyle
View
216
Download
0
Tags:
Embed Size (px)
Citation preview
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.