Wharerau said he has been interested in science and maths his "whole life".
"I had a natural curiosity in everything really," he said.
"I used to have an obsession with counting things and so mathematics came naturally with that, forming equations out of everything I see. I see maths everywhere."
Wharerau, who grew up in Kaikohe and is of Ngāpuhi descent, said he spent the entire year preparing for his NZQA scholarship exams, which he sat in addition to five level 3 NCEA exams (he aced those too).
"It was a lot of extra time after school, staying late almost every day, a lot of weekends given up to go study at school with very caring teachers who I owe most of it to.
"To do scholarship subjects you have to first entirely learn the level 3 course, because the scholarship is built on top of that. That meant to properly prepare for a scholarship subject I had to finish, or know, at least all of the level 3 by term two," he said.
In Northland 93 students were enrolled to sit scholarship exams, but statistics on how many passed were not available at edition time yesterday.
Only about 3 per cent of Year 13 students nationally are awarded the scholarships.
Wharerau said he has always done well at school but scholarship exams challenged him and when he finally sat the exams he was "nervous".
"I was sort of in an empty room by myself, just sitting there with the examiner. I was kind of scared. When you study just before an exam the only thing you ever really pick up is what you don't think you know. So I was very nervous."
Wharerau said when he found out he had passed all three of his scholarship exams, he was "shocked".
"When I walk into a level 3 exam I can almost tell what I'm going to get before I leave, but with the scholarship exam - I had no clue," he said.
In order to retain his scholarship, Wharerau must maintain at least a B grade average each year of his tertiary study.
As Okaihau College's 2018 Dux, Wharerau also received a $6000 P and SM Bullen and Sons Family Trust scholarship.
He said it felt "really good" to be studying a degree centred around the subjects he has always been interested in.
"It makes me feel proud of all my achievements so far and it is a huge confidence boost going in to university to know I can work at high levels and I will be fine."
Wharerau's advice to other students from small towns was "give everything a shot".
"I'd just say go for it and try their hardest. Even if they don't pass, it will be one of the most rewarding experiences. Scholarship exams are something else," he said.