Children can learn math joyfully with friendly natural animals and 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.)