Mathematics
Telescoping Series
Quick fact
The name 'telescoping' comes from the way a collapsible telescope folds into itself—just as the series collapses into a simple expression after most terms vanish.
Why this is interesting
You've added fractions like 1/2 + 1/6 + 1/12 + ... and noticed the sum seems to approach 1. But why? The answer lies in a clever cancellation called a telescoping series.