Here is an ordinary blackboard on which they write using chalk. It is filled with numbers and mathematical signs and jokers. At the bottom there is a free line on which you must put numbers and signs in order to form the correct example. If the result is correct, you will receive points. Please note that time is limited, but after a successful example, the scale will be restored every time. The longer the drawn up example, the more points you earn, ideally. If the whole line is filled. Joker - a set of mathematical actions in one cell, can replace any character in Chalkboard Sums.