Is “Summing” a Scrabble word?
Yes
SUMMING
Valid in at least one Scrabble dictionary
Valid in these dictionaries
SOWPODS / CSW
Scrabble UK & International
TWL / NWL
Scrabble North America
Large English Dictionary
General English word list
Meaning of Summing
verb
1.To add together.
2.To give a summary of.
Synonyms: add, add together, add up, sum up, summate, tally
noun
1.The act or result of addition; a sum.