w1 - lesson 3: fractions and mixed numbers 7 - week 1...3. 4 6, 6 9, and 8 12 are all equivalent...
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V6-10
Mathematics Grade7W1-Lesson3: FractionsandMixed
Numbers
ImportantConceptsofGrade7Mathematics
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Mathematics Grade 7Version 6Preview/Review W1 - Lesson 3ISBN 1-894894-75-8
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W1 - Lesson 1 ........................................................................Divisibility RulesW1 - Lesson 2 ...................................................................... Decimal NumbersW1 - Lesson 3 .....................................................................................FractionsW1 - Lesson 4 ................ Improper Fractions, Mixed Numbers,Percents, andDecimalsW1 - Lesson 5 .................................Integers, Number Lines, and SequencingW1 - Quiz
W2 - Lesson 1 ..................... Table of Values and Graphing Linear EquationsW2 - Lesson 2 ...............................Modeling Expressions, Equations, and thePreservation of EqualityW2 - Lesson 3 ..................................................Algebra and Linear EquationsW2 - Lesson 4 .....................................................................................StatisticsW2 - Lesson 5 .............................. Circle Graphs and Calculating ProbabilityW2 - Quiz
W3 - Lesson 1 .........................................................................................CirclesW3 - Lesson 2 ...................................... Area of Triangles and ParallelogramsW3 - Lesson 3 ............................................................................Line Segments W3 - Lesson 4 ..................................Parts and Plotting on a Cartesian PlaneW3 - Lesson 5 .........................................................................TransformationsW3 - Quiz
MaterialsRequired
Math SetCalculator
ImportantConceptsofGrade7Mathematics
NoTextbookRequired
Thisisastand-alonecourse.
Preview/Review Conceptsfor
Grade Seven Mathematics
W1 – Lesson 3:
Fractions and Mixed Numbers
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Preview/Review Concepts W1 - Lesson 3 MathematicsGrade7
W1 – Lesson 3: Fractions
Warm-up:
• Icanusepatternblockstomodelfractions.
Fraction Tiles
How many?
1. are in ? _______ 2. are in ? _______
3. are in ? _______ 4. are in ? _______
5. are in ? _______
Based on the relationships above,
1. If = 1. = _______
2. If = 1. = _______
3. If = 1. = _______
4. If = 1. = _______
Preview/Review Concepts W1 - Lesson 3MathematicsGrade7
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Now, try some really fun shapes.
1. If + = 1, what is ? _______
2. If + = 1, what is + ? _______
3. If + = 1, what is + ? _______
4. If + = 1, what is ? _______
5. If - = 1, what is + ? _______
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Preview/Review Concepts W1 - Lesson 3 MathematicsGrade7
Review:
• Iunderstandfractionbasics.
Practice
Example 1: What fraction of the pie has been removed?
One of eight pieces has been removed; therefore, 18
has been removed.
Example 2: What fraction of the eggs is left in the carton?
Ten of twelve eggs are still in the carton; therefore 1012
or 56
is left in the carton.
3 numerator or dividend vinculum 7 denominator or divisor
properfraction: a fraction in which the numerator is lessthan the denominator Example: 2
3
mixednumber: the sum of a whole number and a proper fraction
Example: 647
improperfraction: a fraction in which the numerator is greaterthan the denominator Example: 7
2
vinculum: the line between the numerator and the denominator, showing that the two numbers are connected
Preview/Review Concepts W1 - Lesson 3MathematicsGrade7
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Equivalent Fractions
Example: Write three equivalent fractions for 23
.
46
, 69
, and 812
are all equivalent fractions of 23
.
Multiplying or dividing the numerator and denominator by the same number can generate an unlimited number of equivalent fractions.
Practice
Fill in the blanks to complete the equivalent fractions.
a. 23 15= b.
17 21=
c. 4 18= d. 5 10
12=
e. 7
11 33= f.
618 9
=
g. 8
20 5= h.
33 199
=
i. 2 4
10= j. 3 21
28=
Fractions that represent the same amount are called equivalent fractions.
2 4 2 6 2 8 3 6 3 9 3 12
X 2
X 2
X 3
X 3
X 4
X 4
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Preview/Review Concepts W1 - Lesson 3 MathematicsGrade7
Reducing Fractions to Simplest Form
Example: Write the fractions in lowest terms.
a. 9 and 12 are both divisible by 3.
The simplest form of 912
is 34
.
b. 712
Because 7 and 12 do not have any numbers by which they are both divisible, the fraction is already in its simplest form.
Practice
Express each fraction in lowest terms.
a. 2 4= b. 4
12=
c. 6 9= d. 5
15=
e. 7 21
= f. 10 18
=
g. 8 24
= h. 50 100
=
i. 312
= j. 5 25
=
A fraction in simplest form is the fraction that cannot be divided to �nd an equivalent fraction.
9 312 4
3÷
3÷
A fraction in simplestform is also known as a reducedfraction or a fraction expressed in lowestterms.
Answers should always be given in lowestterms.
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Preview/Review Concepts W1 - Lesson 3 MathematicsGrade7
Objective:
• Icanaddandsubtractfractionswiththesamedenominators..
Practice
Solve. Express your answers in lowest terms..
a. + =1 13 3
b. + =1 57 7
c. + =2 49 9
d. 5 3
10 10+ =
e. 1 36 6+ = f. 11 5
20 20+ = g. 3 2
8 8+ = h. 10 8
12 12− =
i. 17 821 21
− = j. 13 315 15
− = k. 9 510 10
− = l. 7 29 9− =
Subtracting fractions with the same denominator.
Keep the denominator the same; subtract the numerators.
Example: 7 312 12
−
7 3 47 3 4 Therefore, 12 12 12
− −
Adding fractions with the same denominator
Keep the denominator the same; add the numerators.
Example: 1 24 4
1 2 31 2 3 Therefore, 4 4 4
Preview/Review Concepts W1 - Lesson 3MathematicsGrade7
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Objective:
• Icanaddandsubtractfractionswiththedifferentdenominators..
Practice
Solve. Express your answers in lowest terms..
a. 2 13 7+ = b.
1 36 4+ =
c. 1 42 9+ = d.
6 310 8
+ =
e. 5 5
20 8+ = f.
3 221 3
+ =
g. 10 112 4
− = h. 17 521 7
− =
i. 9 3
10 20− = j.
7 19 3− =
2 8 10 40
7 35 8 40
Example 1: You need a common denominator. 8 and 10 are both factors of 40.
Change:
Change: Subtract:
7 28 10−
35 8 2740 40 40
−
1 3 4 12
Example 2: Common denominator: 12
Change:
Add: OrCommon denominator: 4
Change:
Add:
1 34 12
3 3 6 112 12 12 2
1 1 2 14 4 4 2
3 1 12 4
Preview/Review Concepts W1 - Lesson 3MathematicsGrade7
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Objective:
• Icanmodeltheadditionandsubtractionoffractions.
Grid Model
Note: Use the columns and rows of a grid to represent different denominators.
Example 1: 1 13 4+ =
Example 2: 3 15 3− =
Practice
Draw the grid that represents best the solution. For this activity you do not need to simplify the fraction.
a. + =1 13 3
b. + =1 57 7
c. + =2 49 9
Total squares = 12Number of shaded squares = 7
Answer = 7
12
Total squares = 14Number of shaded squares left = 4
Answer = 4
15
1 of 3 rows = 14
colour in 4 squares 1 of 4 columns = 13
colour in 3 squares
3 of 5 rows = 35
colour in 9 squares1 of 3 columns = 1
3erase 5 squares
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Preview/Review Concepts W1 - Lesson 3 MathematicsGrade7
d. 1 24 3+ = e. 1 3
5 4+ = f. 1 3
3 10+ =
g. 3 14 3− = h. 4 2
5 3− = i. 6 2
7 6− =
j. 8 49 6− = k. 7 1
8 2− = l. 2 1
3 4− =
Preview/Review Concepts W1 - Lesson 3MathematicsGrade7
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Summary and Practice:
• Usingwhatyoulearnedanswerthefollowingquestions.
1. On the chart below, summarize the steps needed to add or subtract fractions with the same denominator and fractions with different denominators.
Same Denominators Different Denominators
Steps to add fractions
Steps to subtract fractions
2. Express the fractions in lowest terms.
a. 618
b. 954
c. 1648
d. 1421
3. Using the grid below, write an addition equation represented by the grid.
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Preview/Review Concepts W1 - Lesson 3 MathematicsGrade7
4. Model using a grid.
a. 3 16 3+ b. 9 3
10 4−
5. 13
of entries in a pet show are cats. 12
of the entries are dogs.
What fraction of the animals is not a cat or a dog?
6. George spent 28
of his spare time playing video games, 26
practising basketball, 14
practising guitar, and the remainder watching TV. What fraction represents the time he spent watching TV?
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