standard_description: Interpret multiplication as scaling (resizing), by:
- 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.
- 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.
problem_activity: Task
In a marching band there are 24 trombones and 15 snare drums.
Heather says, “The ratio of trombones to snare drums is 24:15.” Audrey says, “No, the ratio of trombones to snare drums is 8:5.” Who is right, and why?
A different marching band has 30 snare drums, but its trombone to snare drum ratio is the same as the first marching band. How many trombones does it have?
Explain what these ratios all have in common:  8:5, 16:10, 24:15. Create a diagram to support your answer.
Mathematicians call these “equivalent ratios.” Come up with a new set of ratios that are equivalent to 6:21.
Explain in your own words the meaning of “equivalent ratios.”


aligns: no