Contour Map

Title: Contour Map

Rating: 2/5

This product puzzle reminded me of what are called level sets in a multivariable Calculus class.  If you haven't taken such a course, you might think of the regions as those in a topography map.

The official rules:

• The digits 1 through 9 appear in each row and each column exactly once.
• Digits in each shaded region must multiply to the indicated product.   
• Squares with multiple colors contain a number that’s used in the product for adjacent regions of each of those colors.  
• Remember: numbers can repeat within a shaded region if that doesn't violate the first rule.