Adjust the numerator and denominator sliders to identify the fractions you wish to multiply.
Then click the "Move A to B" button to move A to B. (Or you can drag A to B.)
When A and B coincide, the product of the fractions appears below the figure.
Notice the “intersection” of the two fractions.

1. Reset A. Select the product of these fractions: 3/7 and 2/3.
2. How many small rectangles (in all) will there be when you move A to B?
3. How many are there in the intersection (the overlap area)?
4. Now move A to B. Did you correctly predict the answers to #2 and #3?
5. Suppose you were multiplying x/3 and y/8?
6. How many small rectangles (in all) will there be when you move A to B?
7. Suppose you were multiplying 2/m and 5/n?
8. How many small rectangles will appear in the intersection (the overlap area)?
Chuck Friesen, University of Nebraska-Lincoln
chuckfriesen@gmail.com