fractions. proportional reasoning number sense are 1.7 and 1/7 the same or are they different? ...
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Proportional Reasoning
Number Sense Are 1.7 and 1/7 the same or are they different? Are 0.5 and 6/12 the same or different? Order the following numbers from largest to
smallest: 0.48, 5/8, 14/13, 0.99. What is 5 + ½ +0.5 = ? Are there any fractions between 2/5 and 3/5? Are there any decimals between 2/5 and 3/5? Are there any decimals between 0.46 and 0.47? Are there any fractions between 0.46 and 0.47?
Fractions Chapter
Fractions Analysis Rewriting Fractions Operations—Adding and Subtracting Operations—Multiplying Operations—Dividing
Fractions Chapter
Terminology (page 241)NumeratorDenominatorProper fractionMixed numberGCF (Greatest Common Factor)LCD (Least Common Denominator)
Today
Jigsaw activity 4 groups
Fraction analysis Rewriting fractions Adding/fubtracting fractions Multiplying/dividing fractions
Today
Jigsaw cont. 30 minutes to identify
Preskills General teaching procedures Diagnosis and remediation Corrections Example selection Develop a 5 min. activity for the group
Fractions Analysis
Instruction begins around second grade and includes: Part/whole Writing a faction for a diagram Reading fractions Determining if fraction is >, <, = to one
whole Reading mixed fractions
Fractions Analysis
Important features: Proper and improper introduced
concurrently Initial instruction is to interpret a fraction Initially fraction instruction is figures
divided into parts
Fractions AnalysisWriting Fractions Format 12.3
Part A: Students learn parts of fraction B & C: Daily practice for several weeks
Model Format 12.3 Example selection guidelines
Vary the number of parts in each whole, number of wholes, and number of parts shaded
Include proper and improper fractions
Fractions AnalysisDrawing Diagrams
Drawing diagrams to represent fractions Teacher models how to divide circles
into equal parts Worksheet, dividing circles and shading
parts used
Fractions AnalysisDecoding Fractions
Decoding fractions (traditional)Format 12. 4
Teacher models reading fractions and tests students
Fractions AnalysisMore, Less, Equal to OneFractions that are more than one, less
than one and equal to oneFormat 12. 5
Part A: PicturesPart B: Rules Part C: Structured Worksheet
Model 12.5, B
Fractions AnalysisMixed Numbers
Reading and writing mixed numbersFormat 12. 6
Part A: Picture demonstrationPart B: Teacher models and tests reading mixed fractions Part C: Writing numbers
Rewriting Fractions
Identify missing numerator in an equivalent fraction
What are/is Equivalent fractions Reducing fractions Converting mixed fractions to improper
and vice versa
Rewriting FractionsEquivalent Fractions
What is the basic strategy?What are the specific preskills?
3 = 4 12
3 3 = 9 4 3 12
x
Rewriting FractionsEquivalent Fractions
Format 12.7 teaches the rule for factions equal to 1:
When the top number is the same as the bottom number, the fraction equals 1.
Rewriting FractionsEquivalent Fractions
Format 12.8 teaches: Part A shows the concept of equivalent
fractions Part B teaches the rule—When you
multiply by a fraction that equals 1, the answer equals the number that you start with.
Part C is the structured presentation of the strategy
Rewriting FractionsReducing Fractions
Two stages:1. Introducing greatest-common-factor
(What does GCF mean?)2. Reducing fractions when GCF is
difficult to determine
Rewriting FractionsReducing Fractions
Greatest-common-factorFormat 12.10—define GCF and lead students in finding
Rewriting FractionsReducing Fractions
Format 12.11 Part A, teacher presents the strategy
(model) Part B, the structured worksheet What are the example selection
guidelines for Format 12.11?
Rewriting FractionsReducing Fractions
What strategy do we teach for reducing fractions with big numbers (those with difficult GCF)?
45 = (5) 9 = (3) 3 = 3 75 (5) 15 (3) 5 5
Rewriting Fractions: Converting Mixed Numbers and Improper Fractions
What is a mixed number?What is an improper fraction?
What is the procedure for converting an improper fraction to a mixed number?
Format 12.12:Part A shows the concept in picturesPart B teaches the strategyPart C is a worksheet
Rewriting Fractions: Converting Mixed Numbers and Improper Fractions
Format 12.12:What are the example selection guidelines?
Rewriting Fractions: Converting Mixed Numbers and Improper Fractions
What is the procedure for converting mixed numbers to improper fractions?
Format 12.13Part A is converting a whole numberPart B is converting a mixed number
Rewriting Fractions: Converting Mixed Numbers and Improper Fractions
Operations—Adding and SubtractingThree basic problem types of
addition/subtraction problems1. With like denominators2. With unlike denominators with easy
lowest-common denominators3. With unlike denominators and difficult
lowest-common denominators
Operations—Adding and SubtractingLike denominators:Format 12.14 teaches students (at this
point) only to add or subtract fractions in which the whole has the same number of parts.
Worksheets should include problems with unlike denominators—why?
Operations—Adding and SubtractingFractions with unlike denominators:
Format 12.15 teaches students to find the least common multiple by skip counting for each denominator and selecting the smallest common number.
3 + 14 5
Operations—Adding and SubtractingAdding and subtracting fractions with
unlike denominators, Format 12.16:Part A, teacher demonstrates finding the
LCM, multiplying both fractions by a fraction of 1, and then adding.
Part B and C are worksheets.
Operations—Adding and SubtractingAdding and subtracting fractions with
unlike denominators, Format 12.16:What are the example selection
guidelines?
Operations--Multiplication
Three problem types:1. Multiplying proper fractions2. Multiplying a fraction and a whole number3. Multiplying one or more mixed numbers
Operations--Multiplication
Multiplying proper fractions:Students are taught the simple rule:
Work the top times the top and the bottom times the bottom.
Include multiplying proper fractions with addition and subtraction of fractions on worksheets.
Operations--Multiplication
Multiplying fractions and whole numbers:Format 12.18:
Part A teaches changing a whole number to a fraction: 5 = 5/1Part B and C worksheets, students change whole number to a fraction, multiply, and covert the answer to a mixed number.
Operations--Dividing
Model of the strategy that illustrates the rationale as well as the procedures (not included in the book)
Operations--Dividing
Preskills:Identity element: 1 x a = aFraction of one has same number top and bottom: a/aAny number divided by 1 equals that numberMultiplying fractionsReciprocals: a x b = ab = 1
b a ab
Diagnosis and Remediation
What are the following patterns of errors? What are examples? (Page 268)
Computational Component-skill Strategy
Diagnosis and Remediation
Expand the remediation for Summary Box 12.4
What skills would you teach (often an isolated skill)
What types of problems would you include in your remediation practice problems?
What types of problems would you include in the final problem set?
Decimals
7 areas:1. Reading and writing decimals and mixed
decimals2. Converting decimals to equivalent
decimals3. Adding and subtracting decimals4. Multiplying decimals5. Rounding off decimals6. Dividing decimals7. Converting between decimals and fractions
Decimals
What are the preskills for all decimal areas?
What decimals skills are preskills for all other decimal areas?
Reading and Writing Decimals:Reading Tenths and Hundredths
Format 13.1: Structured board: Teaches the rule that
one digit after the decimal tells about tenths and two digits after the decimal tell about hundredths
Structured work sheet: Given a decimal students identify the fraction and visa versa
Reading and Writing Decimals:Reading Tenths and Hundredths
Format 13.1:What example sets should be used for this
format?What critical behavior must the teacher
emphasize?
Reading and Writing Decimals:Writing Tenths and Hundredths
Format 13.2Part A: Teacher demonstrates how to
write a fraction as a decimal Part B: Less structured worksheet, given a
fraction, writing a decimalWhat examples should we include?
Reading and Writing Mixed Decimals: Tenths and Hundredths
What must the students be able to do (preskills)?
Format 13.3: Part A: Teacher demonstrates reading mixed
numbers emphasizing and between whole number and decimal
Part B: Given a mixed fraction student writes decimal and/or given words students write the mixed decimal
Reading and Writing Decimals:Representing ThousandthsSame procedures as Formats 13.1 and
13.2:
What should the initial examples be like?After several lessons what examples
should be added?
Equivalent Decimals
What are equivalent decimals?What are equivalent decimal skills needed
for? Format 13.4:
Part A: Rationale for adding zeros (.3 = .30)
Part B: Structured board for rewriting decimals
Part C: Worksheet with column chart
Adding and Subtracting Decimals and Mixed DecimalsTypes of problems:1. Both numbers have the same number
of decimal places2. Numbers have different numbers of
digits after the decimal point
Adding and Subtracting Decimals and Mixed DecimalsBoth numbers have the same number of
decimal places: Teach students to align problems
vertically Students write the decimal place
directly below other decimal points Problems oriented horizontally are
rewritten vertically and worked as above
Adding and Subtracting Decimals and Mixed DecimalsNumbers have different numbers of digits
after the decimal point:What does this require?
Adding and Subtracting Decimals and Mixed DecimalsNumbers have different numbers of digits
after the decimal point:Format 13.5What examples should we include?
Rounding Off Decimals
What is rounding off a preskill for?Format 13.61. Determine how many digits will be
after the decimal place2. Count the number of digits and draw a
line3. If the number after the line is 5 or
more, “round up”
Rounding Off Decimals
What are the 3 example selection guidelines?
What type of numbers are particularly hard to round off?
Multiplying Decimals
What is the “tricky” part of multiplying decimals?
Format 13.7: Part A: Teaching students the rule for
determining where the decimal point goes in the answer
Part B: Structured worksheet, students determine where to put the decimal point in completed multiplication problems
What examples could be confusing?
Dividing Decimals
4 categories of problems, what are examples of:
1. No remainder & no conversion2. Conversion required to solve without
remainder3. A remainder that requires rounding4. Divisor is a decimal
Dividing Decimals
No remainder & no conversion: Rule: Decimal in answer goes directly
above the decimal in the number being divided
Teacher leads students
What are the example selection guidelines?
Dividing Decimals
Conversion required to solve without remainder—students must rewrite the dividend as an equivalent decimal to avoid a remainder.
Tell students will work until no remainder
Model What are the example selection
guidelines?
Dividing Decimals
A remainder that requires rounding Format 13.8
Part A: Students read the directions, determine how many digits in the answer, work the problem until they have that many digits, draw a line, work one more digit so that they can round off
Special consideration is given to what type of problems?
Dividing Decimals
Divisor is a decimalWhat must be done to solve these
problems?What is the preskill?
Dividing Decimals
Divisor is a decimal Preskill, 13.9—multiplying
decimals by multiples of 10 Part A: Rule about moving the
decimal Part B: Structured worksheetWhat types of examples should be
included?
Dividing Decimals
Divisor is a decimal Format 13.10
Part A: Teaches that you can’t divide by a decimal, then shows how to divide
Part B: Structured worksheetWhat are the two example selection
guidelines?
Converting Fractions and DecimalsWhy teach this?What are the two preskills?What is the rule for converting fractions
into decimals?What examples should be included?