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