Elementary school math riddle: the answer isn't zero

Mathematical and logical riddles have gained considerable popularity online recently. They offer an engaging and enjoyable way to exercise our brains. A task, simple at first glance, has recently made its appearance on the internet.

Many students don't have a fondness for mathematics as it's often associated with difficult tasks, complex rules, or strict teachers. However, engaging riddles present a simple, enjoyable way to appreciate solving tasks years after leaving school.

Mathematical riddles have become a significant internet sensation in recent months. Even persons who weren't fans of school math are now enjoying the exercise of their logical and creative thinking via these riddles.

The puzzles currently dominating the internet often start as equations that appear extremely simple at first glance. These tasks usually match the level of elementary school students. It's not surprising that people easily get lost in them, making a simple mistake or forgetting the correct order of operations.

A recently popular riddle is a rather unusual equation consisting solely of nines:

9 - 9 ÷ 9 + 9 - 9 ÷ 9 = ?

Most online users suggest the answer is zero, a result you'd arrive at by solving the equation from left to right. But this isn't correct.

We must recall the order of operations. Regardless of the sequence from left to right, we first perform operations in parentheses, then exponentiation and rooting, then multiplication or division, and finally adding or subtracting. Thus, the riddle should be solved as follows:

9 - 1 + 9 - 1 = ?

8 + 9 - 1 = ?

17 - 1 = 16