Simple Calculation

Features Simple Calculation

To a child for study use to an adult of the head is done gymnastics.Because I count a number, I have one column of addition, subtraction, multiplication table.Will the child disliking study study with a smartphone.Because the basics of arithmetic are the most important places, let's study well.
As a brain trainig, several are solved before time, or adult will challenge it.Do you not do the exercises of the head several times a day?