Children can effectively learn math with friendly natural animals and/or worms.The comprehensive game to travel through billions of years, meeting the trilobites, dinosaurs, etc. is provided. The player may face the hazards like "the time dragons" and/or "time thunder". Incorrect answers or too late answers make it difficult to return back to the present world. The articles contained are such as:the percentage, fractional additions and substraction, rounding, the multiplication of decimals and integers, decimal division, geometry workshop( trapezoid, parallelogram, rhombus, the area of triangle, parallelogram, circle, etc.)