Some math olympiad problem requires a deeper reasoning so that children do need lots of practice. Here are examples of questions used in the National Science Olympiad (OSN) in mathematics.

- Five goats eat the grass area of 5 times the size of a football field within 5 days. How many days needed by the three goats to spend the grass area of 3 times the size of a football field?
- Budi ran three times faster than walking speed Iwan. Suppose Iwan, who is more intelligent than Budi complete the exam at 2:00 and started walking home. Budi complete the exam at 2:12 and ran after Iwan. At what time exactly will follow Iwan Budi?
- Suppose N is the smallest integer that is: left over 2 if divided by 5, trace 3 when divided by 7, and left over 4 when divided by 9. What is the sum of digits N?
- To determine its representatives in the branch run 110 m goalkeeper son, a high school held a selection followed by 5 students. The selection is held three times a race at every race, the fastest runner was given a score of 5, while ranking in the bottom row have a value of 3, 2, 1, 1. No two runners occupy the same rank. If the winner selection is given to the highest overall score in the third race, what is the lowest value that may be achieved by the winner selection?
- A family consists of father, mother, and several children. The average age of the family is 18 years old. Without a father who is 38 years old, the average age of the family is 14 years old. How many children in the family?
- A conference was attended by 47 guests. There are several male guests and a few female guests. The first guy 16 Guests know female guests, both male guests know 17 female guests, and so on until the female guests last man known throughout the female guests. Determine the number of female guests last known male guests.
- Known to all natural numbers n is not more than 6. A six-digit number, say X, when multiplied by a clear digits the same. If X is multiplied by 2, the same digits, but the order is changed. If X is multiplied by 3, the digits are also equal, but the order is changed. Until if X multiplied by n, then the same digits, but the order is changed. Determine X!