This app can be used to teach and study the alternative column-addition method used in the Everyday Mathematics curriculum developed by the University of Chicago School Mathematics Project. The app is easy to use and it has an intuitive interactive interface with customizable colors and other settings. The Everyday Column-Addition Method The method is called column-addition method in the Chicago School Mathematics Project but the app is called the Everyday column-addition method to distinguish it from the standard column addition method. The Everyday column-addition method was developed and shown to the Everyday Mathematics authors by a first grader. The method has two stages. In the first stage the digits are added one column at a time in each column. After the first stage some columns can have two-digit numbers. In the second stage the carries are done to obtain the result. Endorsed by teachers R. Zeni, Ecole Sandy Hill Elementary, Abbotsford, BC, Canada: "The Math apps by Esa Helttula allow students to practice and reinforce the specific computation strategies taught in class, with as much or as little scaffolding as necessary. They also provide individualized feedback to each student, with an immediacy that is not always possible through pencil and paper practice. Being able to adjust the level of difficulty to suit their needs is also very motivating for the students. I am so glad to have come across this great educational tool!"