Students will learn that multiplying a number by a fraction less than 1 scales it down, multiplying a number by a fraction greater than 1 scales it up, and multiplying a number by a fraction greater than 1 has no effect. Here's an example problem: Order the fractions from least to greatest:
$$\dfrac{2}{3} \cdot \dfrac{7}{8}\quad\quad\dfrac{8}{7} \cdot \dfrac{2}{3}\quad\quad\dfrac{5 \cdot 2}{3 \cdot 5}$$Watch these Khan Academy videos:
Fraction multiplication as scaling by Khan Academy
Next, give your students these challenges:
Conclude by leading this investigation:
Integral Centrifuge II (multiplication of negatives)
by MathPickle
5.NF.B.5: Interpret multiplication as scaling (resizing).