To say Ishan Nath is good at maths would be an understatement.
The 15-year-old is one of only six Kiwis selected to represent the country at the International Mathematical Olympiad in Romania in July.
Students from more than 100 countries compete to solve six maths problems.
Sound simple? It's not.
"You're given four and a half hours to solve three problems ranging from relatively easy to relatively hard," Ishan said.