MAFS.5.NF.2.5

Interpret multiplication as scaling (resizing), by:

• 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.
• 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 = (nxa)/(nxb) to the effect of multiplying a/b by 1.