* Assistant Professor of Applied Mathematics, Department of Mathematics, Faculty of Education, Ain Shams University, 2017-Present. * Associate Professor of Applied Mathematics, Department of Mathematics, Faculty of Science, Taibah University(Yanbu), Saudia Arabia, 2011-2017. * Associate Professor of Applied Mathematics, Department of Mathematics, Faculty of Education, Ain Shams University, 2008-2011. * Assistant Professor of Applied Mathematics, Department of Mathematics, Girls College of Education, Qassim University, Saudia Arabia, 2003-2008. * Assistant Professor of Applied Mathematics, Department of Mathematics, Faculty of Education, Ain Shams University, 2002-2003. *Teaching Assistant of Applied Mathematics, Department of Mathematics, Faculty of Education, Ain Shams University, 1998-2002. * Demonstrator , Department of Mathematics , Faculty of Education , Ain Shams University , 1992-1998.