0 +----+----+----+----+ +-----+-----+-----+-----+ | 7 | 8 | 9 | / | | sin | cos | tan | ^ | +----+----+----+----+ +-----+-----+-----+-----+ | 4 | 5 | 6 | * | |sqrt | log | ln | 1/x | +----+----+----+----+ +-----+-----+-----+-----+ | 1 | 2 | 3 | - | | x^2 | pi | e | +/- | +----+----+----+----+ +-----+-----+-----+-----+ | 0 | . | = | + | +----+----+----+----+ | C | +-------------------+