5.NF.5
5. Interpret multiplication as scaling (resizing), by:
a. 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.
b. 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.