Complex sentence: Traditional mathematics has been called a failure because only a small percentage students achieve the highest levels of mathematics achievement such as calculus, and it is believed that not enough master even algebra, which is seen a gateway to high paying jobs such as computer programming.
Split into simpler sentences: Traditional mathematics has been called a failure because only a small percentage students achieve the highest levels of mathematics achievement such as calculus. Some argue that too few students master even algebra, which is seen a gateway to high paying jobs such as computer programming.