Directions: Use the digits 1-9 each once to make a the largest possible sum. Source: Robert Kaplinsky and Ellen Metzger

Directions: Use the digits 1-9 each once to make a true statement. Source: Ellen Metzger

Directions: Use the digits 1 to 9, at most one time each, to fill in the boxes to make two fractions that have a quotient that is as close to 4/11 as possible. Source: Robert Kaplinsky

Directions: Using the digits 1 to 9 at most one time each, place a digit in each box to find the function’s greatest possible value. Source: Robert Kaplinsky

Directions: Using the digits 1 to 9 at most one time each, fill in the boxes to create a fraction as close to one as possible. Source: Peter Morris

Directions:  How many numbers are between 1 and 3? Source:  Robert Kaplinsky

Directions: Fill in the boxes using the digits 1 through 9, at most one time each, to make a true equality statement Source: Bryan Anderson

Directions: The black triangle is a right triangle with legs 8 and 6. The vertices are at the points (0,0), (0,8), and (6,0). The red line segment is perpendicular to hypotenuse. Find the length of the red line segment. Source: Kate Nerdypoo

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

Directions: Using the digits 1 to 9 at most one time each, place a digit in each box to make the least possible difference. Source: Robert Kaplinsky