Directions:  Using the digits 1 to 9 at most one time each, fill in the boxes to make the smallest (or largest) quotient. Source:  Robert Kaplinsky

Directions: Using the digits 1 to 9 at most one time each, place a digit in each box to make the smallest (or largest) sum. Source: Robert Kaplinsky

Directions: Using the digits 1 to 9 at most one time each, fill in the boxes to make the smallest (or largest) difference. Source: Robert Kaplinsky

Directions: Using the digits 1 to 9 at most one time each, fill in the boxes to make the smallest (or largest) product. Source: Robert Kaplinsky

Directions: Using the digits 1 to 9 at most one time each, fill in the boxes to make the smallest (or largest) product. Source: Robert Kaplinsky

Directions: Using the digits 1 to 9 at most one time each, fill in the boxes to make the smallest (or largest) sum. Source: Robert Kaplinsky

Directions: Using the digits 1 to 9 at most one time each, fill in the boxes to make the smallest (or largest) difference. Source: Robert Kaplinsky

Directions: Using the digits 1 to 9 at most one time each, fill in the boxes to make the smallest (or largest) quotient. Source: Robert Kaplinsky

Directions: Create 3 lines that have the same domain. Then, create 3 more lines that have the same range. Source: Dane Ehlert

Directions: Using the digits 0 to 9 at most one time each, fill in the boxes to create a three-digit number. Try to create a three-digit number divisible by the greatest (or fewest) amount of the following factors: 2, 3, 4, 5, 6, 8, 9 or 10. Source: Kelly Zinck