Will a mathematics teacher be rewarded if he intends by his work the face of Allah Almighty?

Studying mathematics, if a Muslim intends thereby to benefit others in their worldly affairs, is an act for which he will be rewarded due to his intention, but its reward does not reach the level of the reward for the Islamic sciences. It is a permissible means, and if this means leads to benefiting people, its doer will be rewarded. What is permissible can become forbidden, disliked, recommended, or obligatory based on what it leads to; thus, what is permissible is lawful if it is a means to a lawful matter, and forbidden if it is a pretext to a forbidden matter.