According to a study by the Finnish Education Evaluation Centre, two-thirds of ninth graders were unable to calculate everyday math problems like price reduction percentages.
The study involved quizzing students with math problems like: "If an item originally costs 50 euros and you get a 30 percent discount, how much will the item cost?" the education centre's evaluation expert Sami Julin explained.
"They can't figure out the discounted price," he said, adding that problem solving and mental arithmetic were not problem-free areas for many students.
"One out of every two students are able to perform mental arithmetic at acceptable levels," he said.
The study also found that while male students consider themselves better at math than their female counterparts, females get better overall grades in the subject.
The ninth grade girls received an average grade of 7.9 , while their male classmates got 7.5 in mathematics.
The centre surveyed 5,000 students from 140 schools across the country in the study.