Welcome to Math 6 Today’s subject is… Decimals and Fractions Mr. Whalen
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- Slide 1
- Welcome to Math 6 Todays subject is Decimals and Fractions Mr.
Whalen
- Slide 2
- Lets start todays lesson with a question: Can you see the
number in this picture?
- Slide 3
- People with normal color vision can see the number 27 in the
picture. Most people with color deficiency (often called color
blindness) have trouble distinguishing shades of red and green.
About 0.05 of men in the world have color deficiency. What fraction
of men have color deficiency?
- Slide 4
- Tough question? Dont worry! You will answer by the end of this
lesson.
- Slide 5
- Slide 6
- First a Quick Review
- Slide 7
- A fraction usually represents a number which is less than one
but greater than zero. Any number between two whole numbers can be
represented by a mixed number. For example: 1 . A mixed number is
what we call an amount that is part whole number and part fraction.
+ =1 Quick review
- Slide 8
- Quick review: a)Integers are whole numbers and their opposites.
The opposite of 1 is -1. The opposite of 25 is -25. The opposite of
-3 is 3.
- Slide 9
- Integers are not decimals. They have no digits to the right of
the decimal point. In the number 628, 8 stands for 8 ones 2 stands
for 2 tens 6 stands for 6 hundreds So 628 represents the sum of 6
hundreds, 2 tens, and 8 ones, or 600 + 20 + 8. Quick review
- Slide 10
- Base 10 is what we call our number system. In the Base 10
number system, all numbers are expressed using the digits 0-9.
Quick review
- Slide 11
- In base 10: The first number to the left of the decimal point
represents the number of 1's. The second number represents the
number of 10's. The third number represents the number of 100's.
The fourth number represents the number of 1000's, and so on. We
refer to this pattern as place value.
- Slide 12
- Here are the place values: As we move to the right, divide by
10. As we move to the left, multiply by 10. We need to understand
this to work with decimals.
- Slide 13
- This is such an important concept, I want to explain it again
very carefully. As we move to the right, divide by 10. As we move
to the left, multiply by 10. 55 The value of this 5 is ten times
greater than the value of this 5.
- Slide 14
- ___, ___ ___ ___. ___ ___ ___ Ones Thousands Hundreds Tens
- Slide 15
- Decimals To find the value of a decimal place, we divide the
value of the decimal place to the left of it by 10. The sequence of
numbers 1000, 100, 10, 1, continues to the left of the decimal
point: 0.1 = 1/10 0.01 = 1/100 0.001 = 1/1000 Quick review
- Slide 16
- ___, ___ ___ _3_. _3_ ___ ___
OnesThousandsHundredsTensTenthsHundredthsThousandth s Divide the 3
in the Ones place by 10, and you have the value of the 3 in the
Tenths place. This pattern continues.
- Slide 17
- Fraction- A number in the form a/b where b 0. (Fractions
represent division.) Mixed Number- A number that contains both a
whole number and a fraction, such as 1 . Key Vocabulary for this
lesson
- Slide 18
- A Terminating decimal, such as 0.75 has a finite number of
decimal places. A Repeating decimal, such as 0.666 has a block of
one ore more digits that repeat continuously. Key Vocabulary for
this lesson
- Slide 19
- Base-10 system Is what we call our number system in which all
numbers are expressed using the digits 0-9. Place value refers to
the value of a digit depending on its place in a number. Examples:
In 675 the value of 7 is 70. In 723 the value of 7 is 700.
- Slide 20
- Integer- The set of whole numbers and their opposites Key
Vocabulary for this lesson
- Slide 21
- Common Fractions and Equivalent Decimals 1/5 1/32/5 3/52/3 4/5
0.2 0.25 0.30.40.50.6 0.75 0.8 A solid line above the digit (or
digits) indicates that the digit (or digits) repeat (s)
forever.
- Slide 22
- You must be able to read any decimal. When you read a decimal,
you say the number, then identify its value by its smallest place
(farthest to the right). Examples: 0.23 is read as 23 hundredths.
(the 3 is in the hundredths place) 0.346 is read as 346 thousandths
(the 6 is in the thousandths place)
- Slide 23
- To write the decimal as a fraction The place name- 10 th s, 100
th s, 1000 th s will be the denominator. In math level 6, we will
be dealing with decimals in the tenths, hundredths and thousandths
place. Examples: 0.76 is written as 0.165 is written as
- Slide 24
- ALWAYS! Write all fractions in simplest form. Divide the
numerator and denominator by their Greatest Common Factor (GCF). I
told you GCF would come in handy!
- Slide 25
- When you divide the numerator by the denominator, you will
usually end up with either a terminating decimal or a repeating
decimal.
- Slide 26
- Guided Practice: Write the decimal as a fraction or a mixed
number: 1. 2.6 2. 0.35 3. 0.80 4. 3.96
- Slide 27
- Guided Practice Answers: Write the decimal as a fraction or a
mixed number: 1. 2.6= 2 3/5 2. 0.35 = 7/20 3. 0.80 = 4/5 4. 3.96 =
3 24/25
- Slide 28
- To convert a fraction to a decimal, divide the numerator by the
denominator. See examples: 34= 0.75 25= 0.4 These two are examples
of terminating decimals.
- Slide 29
- Convert the fraction to a decimal. Divide the numerator by the
denominator. (A fraction represents division.)
- Slide 30
- Slide 31
- In repeating decimals, one or more digits will repeat
infinitely. When you recognize it, draw a line over only the
repeating digits. Writing Fractions as Decimals
- Slide 32
- Guided Practice: Write the decimal as a fraction or a mixed
number: 5. 0.15 6. 1.25 7. 0.43 8. 2.6
- Slide 33
- Guided Practice Answers: Write the decimal as a fraction or a
mixed number: 5. 0.1515/100= 3/20 6. 1.251 1/4 7. 0.4343/100 8.
2.62 6/10=2 3/5
- Slide 34
- Order the fractions and decimals from least to greatest: 0.5,,
0.37 Instructions: Step 1: Rewrite all fractions as decimals. =
0.2, Then it is easy! 0.2, 0.37, 0.5
- Slide 35
- Guided Practice: Order the fractions and decimals from least to
greatest. 9. 2/3, 0.42, 0.78 10. 5/16, 0.67, 1/6 11. 0.52, 1/9,
0.3
- Slide 36
- Order the fractions and decimals from least to greatest. 9.
2/3, 0.42, 0.78 0.42, 0.6, 0.78 10. 5/16, 0.67, 1/6 0.16, 0.3125,
0.67 9. 0.52, 1/9, 0.3 0.1, 0.3, 0.52 2/3 = 0.6 Guided Practice
Answers: 5/16 = 0.3125 1/6=0.16 1/9=0.1
- Slide 37
- Independent Practice: Write each decimal as a fraction or a
mixed number. 1. 0.31 2. 5.71 3. 0.13 4. 3.23 5. 0.5 6. 2.4 7. 0.19
8. 6.5 9. 2.08 10. 2.019
- Slide 38
- Independent Practice: Write each fraction or mixed number as a
decimal. 11. 1/9 12. 1 3/5 13. 8/9 14. 3 11/40 15. 2 5/6 16. 3/8
17. 7/8 18. 4 4/5 19. 5/8 20. 6 1/8
- Slide 39
- Independent Practice: Order from least to greatest. 21. 0.49,
0.82, 22. 0.11,, 0.13 23. 0.125, 0.29, 24., 0.42, 25. 0.94,, 0.6
26., 0.76, 0.31 27. 0.09, 0.1, 28., 0.4, 0.004 29. 0.018,, 3/10 30.
0.45, 0.050,
- Slide 40
- Independent Practice Answers Write each or a mixed number. 1.
0.31 = 2. 5.71 = 3. 0.13 = 4. 3.23 = 5. 0.5 = 6. 2.4 = 7. 0.19 = 8.
6.5 = 9. 2.08 = 10. 2.019 =
- Slide 41
- Independent Practice Answers: Write each fraction or mixed
number as a decimal. 11. 1/9= 0.1 12. 1 3/5= 1.6 13. 8/9= 0.8 14. 3
11/40= 3.275 15. 2 5/6= 2.83 16. 3/8= 0.375 17. 7/8= 0.875 18. 4
4/5= 4.8 19. 5/8= 0.625 20. 6 1/8= 6.125
- Slide 42
- Independent Practice Answers Order from least to greatest. 21.
0.49, 0.82, 22. 0.11,, 0.13 23. 0.125, 0.29, 24., 0.42, 25. 0.94,,
0.6 0.49, 0.5, 0.82 0.11, 0.13, 0.3 0.1, 0.125, 0.29 0.4, 0.42, 0.6
0.6, 0.8, 0.94
- Slide 43
- Independent Practice Answers Order from least to greatest. 26.,
0.76, 0.31 27. 0.09, 0.1, 28., 0.4, 0.004 29. 0.018,, 3/10 30.
0.45, 0.05, 0.31, 0.375, 0.76 0.02, 0.09, 0.1 0.004, 0.045, 0.4
0.018, 0.17, 0.3 0.05, 0.45, 0.84
- Slide 44
- Conclusion: The key to success is achieving mastery over the
numbers and the basic operations. Fractions and decimals are two
ways to represent amounts less than one whole but greater than
zero. Practice converting from one form to another. And comparing
and ordering them.
- Slide 45
- Assignments- 1.Whats the error? Write a COMPLETE explanation. A
student found the decimal equivalent of to be 0.38. Explain the
error. What is the correct answer?
- Slide 46
- Assignments- 2.Write 5/6 and 5/9 as decimals. Show your work.
Explain how you know whether a decimal repeats. Write a COMPLETE
explanation.
- Slide 47
- Assignments- 3.Complete the supplementary practice exercise,
entitled: Skillswise: Comparing Fractions and Decimals
- Slide 48
- Most people with color deficiency (color blindness) have
trouble distinguishing shades of red and green. About 0.05 of men
in the world have color deficiency. What fraction of men have color
deficiency? EASY! 0.05 is five hundredths or That is in simplest
form.
- Slide 49
- Thats all for now! Be sure to complete all of the assignments.
See you next time.