Sudoku for Little Kids

Recently while surfing Amazon, I was tempted to buy a book called Preschool Sudoku.  Then I realized that the last thing my kids (3 years old) need is another workbook (we have piles and piles of them), and I could totally teach them how to play basic Sudoku myself using things we already have around the house.  Here's how I taught my Preschoolers Sudoku in one evening...

First, I had to teach them the concept of rows, columns, and cells in a grid, so I drew my own 2x2 grid on a piece of paper and labeled the rows and columns.  I showed them Row A, and moved my finger along the cells in the row.  Then they copied me and said "Row A".  I did the same for the other row and for the two columns.  Then I asked them to show me "Column 2", etc.. and they already caught on.

Next I showed them that each cell has a name based on its row and column and showed them how to find the name of a cell (for example, B2).  First I asked them to point to a cell I called out, then I gave them some coins to put in a specific cell:

I told them that each type of coin doesn't like to share, so it doesn't want the same type of coin in it's row or column.  I gave them another type of coin and demonstrated how to place them so each type of coin has its own row and column.  I thought this would be a difficult concept for them, but they caught on immediately:

To play their very first Sudoku, I put two coins down in the grid for each girl, and asked them to place the other two coins correctly.  They understood the concept, and when they made a mistake (i.e. two pennies in the same row), they knew how to self-correct.

Then we moved on to a 3x3 grid:

First we played a game where we took turns putting down a coin.  When it was my turn, I talked aloud through my thought process for how to figure out which spots I could put my coin in.  I saw them imitate the same logic when it was their turn (checking which rows and columns were already taken by the same type of coin).  Then I place a couple coins on the board and asked them to fill in the rest on their own.  My 3-year-olds had learned how to play Sudoku (at least on a 3x3 board) in one evening!

The next day, I presented a bigger challenge:

The foam shapes are from a shape sorting activity (from Lauri Toys, I think), and the board is something I made for the twins when they were 1.5 years old for shape recognition.  This time, there was a new rule - that each row and column could only have one of each color.  We took turns placing the pieces.  Sometimes there was no place to put a piece, so we had to figure out which shape could be switched to a new location to make it work (this was a big brain puzzle).  The kids did great:

I discovered that we're missing a piece (and actually the configuration above wouldn't work if we had our orange circle, so I'll have to find the piece or make a replacement), but it was a really good logic exercise for both me and the kids.  Next, I'll have to devise more easy Sudoku boards for them with math manipulatives.  Now that they understand the concept of grids and cell names, I'm also going to teach them a basic version of battleship... fun times!