How about Σ Sigma notation for summation? It's often written with something like...

		pedasmith on April 11, 2018 \| parent \| context \| favorite \| on: Why Does “=” Mean Assignment? How about Σ Sigma notation for summation? It's often written with something like i=1 at the bottom and 1000 at the top to denote the summation from 1 to 1000. The Wikipedia article at https://en.wikipedia.org/wiki/Summation has some examples.