All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
The claim that it is haraam (impermissible) to teach other than Islamic studies, such as Mathematics and the like of worldly fields of knowledge, is a false claim that has no basis in the Sharee'ah. There is no doubt that the worldly sciences are important and are needed for the benefit of people for both their worldly life and their religion.
A group of scholars underlined that learning useful worldly knowledge is a communal obligation on the Muslim nation (some Muslims must learn them). Ibn Al-Qayyim wrote, "For example, people would need a range of professions, such as farming, weaving, construction, and so forth, so the ruler has the right to force them to learn these professions and pay them a fair fee, as the public interest would not be achieved otherwise. It is for this reason that a group of scholars from the Hanbali and Shaafi’i schools stated that learning such professions is a communal obligation because of the need of the people for it."
It is required of Muslims to seek useful worldly knowledge. The fact that the worldly fields of knowledge are taught in schools that the poor cannot afford does not make such schools haraam. In addition, this problematic issue can be resolved by making some kind of a discount for the poor students or establish special schools for the poor for teaching Islamic knowledge or the like of the possible means.
Also, strict separation between Islamic and worldly sciences is quite harmful to Muslim students who wish to obtain academic degrees in worldly sciences to get good jobs and improve their life standard and at the same time wish to learn their religion. In fact, Muslims are in dire need of schools that teach both Islamic knowledge and worldly sciences and maintain the balance between them.
The important thing in this regard is to consult with Muslim experts and skilled specialists in this field and avoid following the opinions of the ignorant who do not have any share of Islamic knowledge nor sound judgment.
Allaah knows best.