Open Middle®
Directions: Using the digits 1 to 9 at most one time each, fill in the boxes to ake the smallest (or largest) product.
Hint
How can we tell whether it would be better to put the larger/smaller numbers in the numerator or denominator?
Answer
Smallest: 1/9 * 2/8 or largest: 9/1 * 8/2
Source: Robert Kaplinsky
the smallest product is 1/31 and the greatest product is 36