Five number games of brain training. Difficulty that go up every day. It is brain warm up for work or study every day. About games: Worm Calc. Trying to establish the formula. Computing, Reaction. Mini Sudoku. Fill 1 to 4 once in that each column, each row, and each of the four 2×2 subgrids. Reasoning, Concentration. Find formula. Choose a correct formula from answers.