These quizzes expose you to numerical logic puzzles. You’ll quickly realize that Algebra is a powerful tool for solving these problems that won’t leave you endlessly guessing-and-checking!

To get your mind racing, what is the sum of all four symbols in the array puzzle below?

Each symbol has a unique and specific value. The numbers next to each row and column represent the sum of the values in that row or column.

We’ll explore the strategies behind “Calcdoku”, where the digits 1 through 4 are used only once in each row and column.

Can you fill in this grid, where + indicates that the numbers in that region must sum to the given value?

By the end, you’ll have seriously sharpened your equation manipulation skills! You’ll be a puzzle master, able to find the value of the yellow triangle in this array puzzle in no time: