Multiplying Fractions
• CCSS.Math.Content.5.NF.B.4
Apply and extend previous understandings of
multiplication to multiply a fraction or whole number
by a fraction.
• CCSS.Math.Content.5.NF.B.4.a
Interpret the product (a/b) × q as a parts of a partition
of q into b equal parts; equivalently, as the result of a
sequence of operations a × q ÷ b. For example, use a
visual fraction model to show (2/3) × 4 = 8/3, and
create a story context for this equation. Do the same
with (2/3) × (4/5) = 8/15. (In general, (a/b) × (c/d) =
ac/bd.)
NUMBER LINES
5/4 IS MADE UP OF FIVE ¼’S
5/4 =
1/4 + ¼ + ¼ + ¼ + ¼
It represents 5 parts in the number
line!
EQUIVALENCE – NUMBER LINE
Equivalence
• Fraction Bars
• http://www.mathplayground.com/Fraction_b
ars.html
Fraction strips
• http://www.taw.org.uk/demo/mathematics/s
hapes/fractionStrip.htm
EQUIVALENT FRACTIONS
• Area Models: Creating Multiplying the
Numerator and Denominator by the same
number.
CONNECTING WHOLE NUMBER MULTIPLICATIONS WITH
MULTIPLICATION OF A FRACTION
• 3 X 7 = 7+7+7
• 3 X 1/3= 1/3 + 1/3 +1/3
• 7/5 = 7 X 1/5
1/3 X 1/2
• What is 1/3 of ½?
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Use a fraction strip to figure it out?
How would you solve it with a number line?
How would you solve it using an area model?
Write a context problem
Learn a Zillion Video
• Multiply whole number by a fraction
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https://learnzillion.com/lessons/3421
Multiply a fraction by a fraction
https://learnzillion.com/lessons/3468
Multiply fraction by mixed numbers
https://learnzillion.com/lessons/3358
• CCSS.Math.Content.5.NF.B.5
Interpret multiplication as scaling (resizing), by:
• CCSS.Math.Content.5.NF.B.5.a
Comparing the size of a product to the size of one factor on the
basis of the size of the other factor, without performing the
indicated multiplication.
• CCSS.Math.Content.5.NF.B.5.b
Explaining why multiplying a given number by a fraction greater
than 1 results in a product greater than the given number
(recognizing multiplication by whole numbers greater than 1 as a
familiar case); explaining why multiplying a given number by a
fraction less than 1 results in a product smaller than the given
number; and relating the principle of fraction equivalence a/b = (n ×
a)/(n × b) to the effect of multiplying a/b by 1.
Multiplication as Scaling
• https://learnzillion.com/lessons/2666
• https://learnzillion.com/lessons/3485understand-multiplication-by-a-fraction-lessthan-one