Nonogram: 10x10

Numbers on two edges, a picture in the middle

The clues along the top and the left give the lengths of the filled runs in each column and row, in order. Work out which cells must be shaded and a recognisable image appears.

Eight designs are available at 10×10: a house, a cat face, a sailboat, a tree, a bird, a mug, a flower with a stem, and a large letter A. They are hand-drawn bitmaps rather than random noise, which is the entire reason a finished grid looks like something instead of a speckle.

One to six puzzles a page.

Where to begin

• Find the biggest numbers first. A clue of 8 in a row of ten leaves only two possible positions, so the middle six cells are filled whichever way it sits. That is free information and it is where every solve starts.
• Mark the definite blanks with a dot or a cross rather than leaving them empty. On a grid with several runs in one line, forgetting which blanks you had proved is how people go wrong.
• Alternate between rows and columns constantly. One confirmed cell in a row often resolves an entire column, and that column resolves two more rows.
• Pencil. Nonograms reward trying a line and backing out of it, and ink does not.

The seed makes a class set

Type any word into the seed field and the same sequence of images comes back every time. Leave it blank and the pick is random.

Which is how you give thirty children the same four puzzles: one seed, one print run, and everybody is looking at the same sailboat when you put the solution up. It also lets you find a puzzle again months later without having kept the PDF.

A Friday logic station

Four puzzles to a page, solutions on, a seed typed in. Six copies of the two-page PDF.

Groups of four take a copy and work through the puzzles in pairs, rotating. At the end the solution page goes on the board and everybody checks their own sailboat, mug, bird and tree at once, which takes about ninety seconds and no marking at all.

Ten to twenty minutes per puzzle is typical at this grid size for most pupils, which is why 10×10 is the useful classroom size: big enough to need real deduction, small enough to finish inside a lesson.

Limits of this page

• 10×10 only. Smaller 5×5 grids and larger 15×15 ones are separate pages in the logic puzzles category.
• Eight designs, fixed. Changing the seed reorders them; it does not invent new ones.
• No custom images. You cannot upload a photograph or turn a word into a grid.
• Every puzzle has exactly one valid solution. The bitmaps were drawn to avoid ambiguity, which is why the library is curated rather than generated.