There is provided a matrix division method used by a computer that performs processing for computing a matrix equation including a sparse matrix as a coefficient matrix. The matrix division method includes acquiring, from a storing unit, a threshold used to determine the multitude of non-zero elements included in each of rows of the sparse matrix; identifying, within the sparse matrix, a first row whose count of non-zero elements is larger than the threshold; extending the sparse matrix by dividing the identified first row into a plurality of second rows; and dividing the extended sparse matrix into a plurality of row groups and assigning a process being an executable unit of the processing to each of the row groups.
