Quadsum is a math puzzle game designed by Hilaria and Ludi and can help students learn algebraic reasoning, logic, and the basic elements of combinatorics. Quadsum supports many NCTM standards.
Object of Quadsum is to enter an number from 1 to 9 in each of the quad (small squares). The four quad numbers at the corners of a sum (large) square must add up to that sum number, and there can no duplicate quad numbers for that sum number.
A Quadsum puzzle can contain up to 21 sums (the numbers from 10 to 30), [Read More...]