Open Middle®

Summation of Product Values

Directions: Using the digits 0 to 9, at most three times each, place a digit in each box to make the equation true.

How does the relationship between the upper limit and multiplier affect the sum?

There are many answers. One example is an upper limit of 6 and lower of 3, with a multiplier of 3, equals 9 + 12 + 15 + 18.

Source: Owen Kaplinsky

Directions: Using the digits 1 to 9, at most one time each, place a digit …