eiPie Innovations

Combining the imaginary and non-rational, with knowledge, to create real solutions


Cyfr (the game previously known as "Numbers")

Now available as an iPhone®/iPad® app!

A Pastime with a Purpose

The math in the grid below is simple - only addition and subtraction. The challenge, and the pleasure, is in figuring out a solution using the available resources (i.e., the integers 0 - 11). While Cyfr was developed to provide an entertaining way to practice basic math, the essence of Cyfr is not in the math, but in the type of thinking that is required.

As a simple example, if the above table is simply filled with 0 through 11 in sequential order, each equation evaluated (rows, left-to-right; columns, top-to-bottom), and the results summed, the grid has a value of 4.

Select Desired Difficulty Level:

Introductory A Little Harder More Challenging If the Others Were Too Easy

Grid Total:

# of Ways:


  Max Grid Value:


The challenge is take the provided numbers and arrange them so as to maximize the grid value. The basic rules of math apply (i.e., proper order-of-operations must be followed and, when applicable, division by zero is not allowed). How effective are you at getting the greatest possible value out of limited resources?

Are you intrigued by Cyfr? The basics have been described and examples provided. Give it a try and either send an email to let us know your thoughts on the game or, preferably, look for go to the Cyfr (aka "Numbers") Book page, check it out, and order your copy.


Apple, the Apple logo, iPhone, and iPad are trademarks of Apple Inc., registered in the U.S. and other countries and regions. App Store is a service mark of Apple Inc.