Main content

## Riemann sums, summation notation, and definite integral notation

# Summation notation

We can describe sums with multiple terms using the sigma operator, Σ. Learn how to evaluate sums written this way.

If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains ***.kastatic.org** and ***.kasandbox.org** are unblocked.

Main content

We can describe sums with multiple terms using the sigma operator, Σ. Learn how to evaluate sums written this way.