ELI5: Explain Like I'm 5

Harmonic series (mathematics)

A harmonic series is like a big musical orchestra where each person plays a different musical note. In math, it means adding up a bunch of fractions where the bottom number (called the denominator) is a whole number that gets bigger and bigger.

For example, if we start with 1/1 (one over one) and add it to 1/2 (one over two) and add that to 1/3 (one over three) and so on, we get a harmonic series.

The more we add to our series, the larger the sum becomes. However, the series never actually stops or ends because there are infinitely many fractions.

Harmonic series can be used in math to solve complex calculus problems, but they can also be used in the real world. For instance, harmonic series can help us determine how much paint is needed to paint a room.