At first I Made a multiplication exercises app, but for computation by writing at the two-digit addition, my son has so many problems. So I made an app that can practice the calculation by writing of the addition. There are two parts addition and addition carry, and provided the practice of 146 set. There is 20 die in one set, one set one day. I think it provides a set portion of the 96 have carry in particular, to be able to practice carefully. There is also an alarm and statistics function.