Directions: Using the digits 1-6, at most one time each, fill in the boxes to create the largest and smallest combined perimeter/circumference for the rectangle and circle. Source: Christin Smith

Directions: Using the digits 0-9, at most one time each, fill in the boxes so that one rectangle is a scaled drawing of the other. Source: Gian Cavaliere

Directions: Use the digits 1 to 9, at most one time each, to fill in the boxes so that the difference is as close to 50 as possible. NOTE: The digits used in the difference can be repeated. Source: Giselle Garica

Directions: Use the digits 0 to 9, at most one time each, to fill in the boxes so that the sum is as close to 10 as possible. Source: Giselle Garcia

Directions: Use the digits 1 to 9, at most one time each, to fill in the boxes so that the three fractions have a product as close to 1 as possible. Source: Patrick Vennebush

Directions: Use the digits 0 to 9, at most one time each, to fill in the boxes so that the sum is equal to 2 wholes. Source: Joshua Nelson

Directions: Use the digits 1 to 9, at most one time each, to fill in the boxes to get the difference that is as close to 1 as possible. Source: Giselle Garcia

Directions: Use the digits 1 to 9, at most one time each, to create two numbers that have a product as close to 500,000 as possible. NOTE: You may use any length of factors as you would need. Ex 8 digit by 1 digit. 4 digit by 3 digit. Source: Miles Knight

Directions: Use the digits 1 to 9, no more than once, to create three fractions that are as close to zero, one half and one as possible. NOTE: Close as possible is measured by adding up all the differences and making it the least possible value. Source: Darbie Valenti

Directions: Using the digits 0 to 9, no more than one time each, to fill in the boxes to decompose 1 1/10. Source: Christine Jenkins