5.NF.4. - About the Math, Learning Targets, and Rigor

Grade 5 Fractions

5.NF.4

Full Standard

Apply and extend previous understandings of multiplication to multiply a fraction or whole number by a fraction.

  1. 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.)
  2. Find the area of a rectangle with fractional side lengths by tiling it with unit squares of the appropriate unit fraction side lengths, and show that the area is the same as would be found by multiplying the side lengths. Multiply fractional side lengths to find areas of rectangles, and represent fraction products as rectangular areas.

 

Learning Targets (I can)

  • Represent multiplication of a fraction by a whole number.
  • Represent multiplication of a fraction by a fraction.
  • Estimate the product of a fraction by a whole number.
  • Estimate the product of a fraction by a fraction.
  • Multiply a fraction by a whole number.
  • Multiply a fraction by a fraction.
  • Create story contexts for problems involving multiplication of fractions and whole numbers or multiplication of two fractions.
  • Multiply fractional side lengths to find areas of rectangles.

 

About the Math

  • multiplying fractions with countersRepresent multiplication of a fraction by a whole number.
  • Represent multiplication of a fraction by a fraction.

Multiplication with fractions should feature diverse representations. Area models are good for making meaning of the concept. But students should also work with other representations. Fractions of a set may be especially useful for a 

  • Estimate the product of a fraction by a whole number.
  • Estimate the product of a fraction by a fraction.

Estimating products helps us determine if our answers are reasonable. Students should be consistently asked to estimate their products before finding the actual product. After doing so, they should be asked to compare their estimates to the actuals.

  • Multiply a fraction by a whole number.
  • Multiply a fraction by a fraction.

Students should connect the equations/symbols to their representations. As students show understanding, they should begin to work with associated procedures. Students who use procedures to multiply fractions must be able to explain what is happening and what the product means in relation to the factors. 

  • Create story contexts for problems involving multiplication of fractions and whole numbers or multiplication of two fractions.
  • Multiply fractional side lengths to find areas of rectangles.

Connecting area to the multiplication of fractions is very natural. It may be the best place to introduce fractions times fractions. 

 

 

 Math In Minutes:  The video below highlights multiplying whole numbers with fractions.

The Illustrative Mathematics Project task below demonstrates expectation for this standard.

 

 

 

 

Progression of Standard within Grade 5

This progression informs how to develop the standard within the grade level. This progression is provided by HCPSS Elementary Mathematics.

Progression Throughout Year
Quarter 1 Quarter 2 Quarter 3 Quarter 4
 
  • Represent multiplication of a fraction by a whole number.
  • Represent multiplication of a fraction by a fraction.
  • Estimate the product of a fraction by a whole number.
  • Estimate the product of a fraction by a fraction.
  • Multiply a fraction by a whole number.
  • Multiply a fraction by a fraction.
  • Create story contexts for problems involving multiplication of fractions and whole numbers or multiplication of two fractions.
  • Multiply fractional side lengths to find areas of rectangles.

 

 

Progression of this Standard Across Grades

This progression is informed by the Achieve the Core Coherence Map Links to an external site.. Information is not the complete standard.

Progression Across Grades
Grade 4 Grade 6
  • Multiply a fraction by a whole number (4.NF.4)
  • Solve real-world problems by solving equations (6.EE.7)
  • Find the area of triangles and special quadrilaterals (6.G.1)

 

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