### Sums of Consecutive Numbers Puzzle (Tanton: Mathematics)

7 = 3+4 and 30 = 9+10+11. Which numbers are the sum of two or more consecutive counting numbers? (For fun, try 12 and 15 and 32). We answer this puzzle in this video using pictures of dots (though feel free to use algebra instead if you don't like pictures!) And then we can ask ... Which numbers are the sum of three or more consecutive counting numbers?

Length:
09:50