Puzzler: Number Grid Concentration

Observe the grid below. The blank squares should be filled with whole numbers between 1 and 20 inclusive. Any of the numbers may occur more than once, or not at all.

The numbers in every horizontal row add up to the number totals on the right in bold type, as do the long diagonal lines (summing 88 top right and 122 bottom right). Those in every vertical column sum to the numbers in bold type along the bottom.

So. What are the missing numbers?

Total Concentration number grid

What are the missing numbers???

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One response to “Puzzler: Number Grid Concentration

  1. Wow this is tough! I’ve used a simpler concentration number grid for years, on paper. I wanted one that changed the numbers around…we just released a FREE app in itunes called FocusUp that does just that. It’s kind of addicting fun game too…Visit our site, http://www.flyingsofa.com and learn about how to build your concentration and mental toughness with it. Let us know what you think. Since you’re a puzzle maven maybe you can give us some tips.