Multiplying Fractions. CCSS.Math.Content.5.NF.B.4 Apply and extend previous understandings of...
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Transcript of Multiplying Fractions. CCSS.Math.Content.5.NF.B.4 Apply and extend previous understandings of...
Multiplying Fractions
• CCSS.Math.Content.5.NF.B.4Apply and extend previous understandings of multiplication to multiply a fraction or whole number by a fraction.
• CCSS.Math.Content.5.NF.B.4.aInterpret 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 + ¼It represents 5 parts in the number line!
EQUIVALENCE – NUMBER LINE
Equivalence
• Fraction Bars
• http://www.mathplayground.com/Fraction_bars.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?
• 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
• 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.5Interpret multiplication as scaling (resizing), by:
• CCSS.Math.Content.5.NF.B.5.aComparing 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.bExplaining 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/3485-understand-multiplication-by-a-fraction-less-than-one