The Contest Center - SumSum Puzzles

SUMSUM^TM
A New Number and Logic Puzzle

The Contest Center
59 DeGarmo Hills Road
Wappingers Falls, NY 12590

INTRO

       SumSum^TM is a new number and logic puzzle. Your task is to place the black squares and digits into the grid using the clues that are provided.

       SumSum^TM was invented in January 2011 by Frank Rubin, who is the founder of The Contest Center. The name SumSum is the Arabic word for sesame, as in Open Sesame. [Note: each u in sumsum is pronounced as in the word put.] The English word sesame comes from the Arabic sumsum. The name is perfectly suited to this puzzle, because it uses sums in the rows, and sums in the columns, hence SumSum.

THE DIAGRAM

       At first the SumSum^TM diagram is a blank grid, except for perhaps a few digits. You may use these digits as clues to help you fill in the rest of the grid. Each puzzle has a unique solution.

       When you complete the grid there will be two black squares in each line, that is, in each horizontal row and each vertical column. These two black squares will never touch each other. The two black spaces divide the line into 1, 2 or 3 parts, called runs. If both black squares are at the edges of the grid, then there will be only one run. If only one of the black squares is at an edge, then there will be two runs. If neither of the black squares is at an edge of the grid, then they will separate that line into three runs.

       The remaining squares in each line will be white. As you solve the puzzle, you will write one digit into each of the white squares. Each digit will appear only once in any line.

       The numbers to the left of each row and above each column are the sums. Each sum is the total of the digits in each run in that line. The sums are given in order, left to right, or top to bottom. For example, if there are three sums shown to the left of a row, then the first sum is the total of the digits in the first run, the second sum is the total of the digits in the second run, and the third sum is the total of the digits in the third run. For example,

7,3,18

In this example the first run is 4+3, the second run is 2+1, and the third run is 7+5+6. The totals of these runs match the three sums at the left, 7, 3 and 18.

GETTING STARTED

The best way to solve a SumSum puzzle is to start at the edges and work inward. Your first step is to place the black squares. Some black squares can be placed immediately. For example, if a line has only one sum given, then the two end squares in that line must both be black, like this

Another case where you can place a black square immediately is when there are three sums given for a line, and either the first or last sum is 1 or 2. In this case, the end square must contain a 1 or 2, and the next square must be black. For example,

1,8,19	1
12,14,2									2

It is also valuable to mark squares that cannot be black. When a row or column has three sums, the two squares at the ends of that line cannot be black. Often more than one square at the end of a line must be white. Suppose you are solving a 7-digit SumSum^TM, and the sum at the start of a line is greater than 7. Then there must be at least 2 white squares at the start of that line. If the sum is larger than 13, then there must be at least 3 white squares, and so forth. You might mark squares that must be white with a . or - sign, like this

15,3,10

Are you ready to get started? Then click on the links below to go directly to this week's puzzles.

New SumSum puzzles are posted every week
Puzzles for the week starting May 13

We will list the name of anyone
who solves the 10-digit, 11-digit
or 12-digit SumSum puzzle

5-DIGIT SUMSUM
6-DIGIT SUMSUM
7-DIGIT SUMSUM
8-DIGIT SUMSUM
9-DIGIT SUMSUM
10-DIGIT SUMSUM
11-DIGIT SUMSUM
12-DIGIT SUMSUM

Answers: 5-Digit 6-Digit 7-Digit 8-Digit 9-Digit 10-Digit 11-Digit 12-Digit

SOLVERS

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