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# Aggregation - Sum

We saw in the previous lesson, the [stats](https://godoc.org/github.com/apache/beam/sdks/go/pkg/beam/transforms/stats)
package simplifies statistical processing of PCollections.  We continue this exploration by computing the sum of a
PCollection.

**Kata:** Compute the sum of all elements from an input.

<div class="hint">
  Use <a href="https://godoc.org/github.com/apache/beam/sdks/go/pkg/beam/transforms/stats#Sum">
  stats.Sum</a> to compute the sum of elements in a PCollection.
</div>