nonplussed

"He is a student of life."

"The difficult math problem flummoxed Sarah, and she didn't know where to start. "

"The math problem presented a real perplex to the student, leaving him unsure where to even begin. "

"The new policy, surprisingly, unaffected the students' daily routines. "

"The teacher was unimpressed with the student's messy homework and gave it a low grade. "

"Do you need a gift for that special someone?"

"All the different possible options may bewilder us."

"He raised his hand to make his announcement and said "Excuse me everyone, I have an announcement to make."

"The heavy rain was unexpected; we had planned a picnic in the park. "

"The students' high scores on the math test were confounded by the fact that they all had access to the answers beforehand. "

"All the different possible options may bewilder us."

"Quick, grab that umbrella before you get rained on!"