Learning Goal
Part of: Apply and extend previous understandings of multiplication and division to multiply and divide fractions — 2 of 5 cluster items
Apply and extend previous understandings of multiplication to multiply a fraction or whole number by a fraction
**5.NF.B.4**: Apply and extend previous understandings of multiplication to multiply a fraction or whole number by a fraction.
a. Interpret the product (a/b) x q as a parts of a partition of q into b equal parts; equivalently, as the result of a sequence of operations a x q / b. For example, use a visual fraction model to show (2/3) x 4 = 8/3, and create a story context for this equation. Do the same with (2/3) x (4/5) = 8/15. (In general, (a/b) x (c/d) = ac/bd.)
b. 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.
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5.NF.B.4: Apply and extend previous understandings of multiplication to multiply a fraction or whole number by a fraction.
a. Interpret the product (a/b) x q as a parts of a partition of q into b equal parts; equivalently, as the result of a sequence of operations a x q / b. For example, use a visual fraction model to show (2/3) x 4 = 8/3, and create a story context for this equation. Do the same with (2/3) x (4/5) = 8/15. (In general, (a/b) x (c/d) = ac/bd.)
b. 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.
What you'll learn
- Interpret the product (a/b) x q as taking a parts of a partition of q into b equal parts, and connect this to the sequence of operations a x q / b
- Use visual fraction models (area models, fraction strips, number lines) to represent and solve fraction-times-whole-number problems such as (2/3) x 4 = 8/3
- Use visual fraction models to represent and solve fraction-times-fraction problems such as (2/3) x (4/5) = 8/15, and explain why the algorithm (a/b) x (c/d) = ac/bd works
- Find the area of a rectangle with fractional side lengths by tiling with unit fraction squares, and verify that the tiled area matches the product of the side lengths
- Create a story context for a fraction multiplication expression and explain the reasoning behind it
Slides
Interactive presentations perfect for visual learners • Interactive presentation
Slide Video
Watch narrated slides play like a video lesson • Narrated slide playback