High schools should require all students to take four years of math. Even though most students probably not become mathematicians, many of them will choose a profession where math plays an important role. Architects, pharmacists, and carpenters all use math every day. A strong math foundation in high school is important for students to succeed in this, and in other professions.

In one to two sentences, explain which word or phrase should be added to the paragraph to increase it to cohesion, and why that word or phrase would increase cohension

One phrase that could be added to increase cohesion is "Furthermore," because it would help transition the reasoning from the first sentence to the explanation of different professions in which math is important.