Expressions & Equations

Directions: Using the digits 1 to 9 at most twice each, make the sum of the four expressions the greatest possible value. Source: Catriona Shearer

Directions: Using the integers -9 to 9 (excluding 0) at most one time each, fill in the blanks to create two distinct perpendicular lines. Source: Louise Pepper with answers from the students of Kings College Alicante, Spain

Directions: Using the digits 1 to 9, at most one time each, fill in the boxes to make a product that equals 800,000,000. Source: Robert Kaplinsky

Directions: Using the digits 1- 9, at most one time each, to fill in the boxes to make each expression evaluate to a perfect square number. Extension/Challenge: What is the largest/smallest square number you can make? How many different perfect square numbers could be made? Source: Erick Lee

Directions: Using the digits 1 to 9, at most one time each, fill in the boxes to make a true statement. Source: Ryun Deckert and Brock Montgomery

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

Directions: Using the digits 1 to 20, at most one time each, fill in the boxes to create equivalent expressions. Source: Shaun Errichiello

Directions: Using the digits 1 to 30, at most one time each, fill in the boxes to create a system of two linear equations where (3, 2) is the solution to the system. Source: Daniel Luevanos

Directions: Using the digits 0 to 9, at most one time each, fill in the boxes to make a result that is as close to zero as possible. Source: Daniel Luevanos

Directions: Using the digits 0 to 9, at most one time each, place a digit in each box to make a true statement. Source: Daniel Luevanos