Teacher Notes Supplies Needed: Class set of sudoku puzzles. 4 sets squares with the digits 1 – 4. 6 sets squares with the digits 1 – 6. Vocabulary deductive reasoning Supplies Needed:

Before we begin… columns rows

Launch Have you heard of sudoku? How many of you have done sudoku? What is sudoku?

Launch Sudoku has a fascinating history. "Su" means number in Japanese, and "Doku" refers to the single place on the puzzle board that each number can fit into. It also connotes someone who is single—indeed, one way to describe the game is "Solitaire with numbers.”

Launch Although its name is Japanese, its origins are actually European and American, and the game represents the best in cross-culture. Unlike many games which spring from one culture and are then absorbed by others, Sudoku's development reveals it to be a true hybrid creation. See “Daily Sudoku” http://www.dailysudoku.com/sudoku/

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Sudoku 4 x 4 Rules: Each small box has the digits 1, 2, 3 & 4. Each row has the digits 1, 2, 3 & 4. Each column has the digits 1, 2, 3 & 4.

Solve & Justify Row 2 Column 4 PASS OUT THE SUDOKU PAGES AND PAPER NUMBER TILES. http://www.printactivities.com/Kid_Sudoku_Puzzles/Kid_Sudoku_Puzzle_L1_01.html Difficulty Level 1 Do this one together as a class. Have students justify their answers. “Row 1 column 1 must be 1” Each small 2x2 has the digits from 1 – 4, and 2 – 4 are used, so 1 is the only digit missing”. 1 2 3 4 3 4 1 2 2 1 4 3 4 3 2 1

Solve & Justify http://www.printactivities.com/Kid_Sudoku_Puzzles/Kid_Sudoku_Puzzle_L1_01.html Difficulty Level 1 Have student state reasons for where they place the letters.

Solve & Justify http://www.printactivities.com/Kid_Sudoku_Puzzles/Kid_Sudoku_Puzzle_L2_01.html Difficulty Level 2 HINT: The two missing number in the upper left 2x2 square must be 3 and 4 since there is already a 1 and 2 in that square. Now check the rows to see which square can be a 3 or a 4. For example, there is already a 3 in the top row, so the missing number at t he top left can’t be a 3. After the first of the 4 2x2 squares is filled in, continue on with the other 2x2 squares.

Find a Solution & Justify Trade your paper with another pair. Evaluate their solution and justification. http://www.printactivities.com/Kid_Sudoku_Puzzles/Kid_Sudoku_Puzzle_L3_01.html Difficulty Level 3 There are 2 solutions to this puzzle 4 2 3 1 4 2 3 1 1 3 2 4 1 3 2 4 2 4 1 3 3 4 1 2 3 1 4 2 2 1 4 3

Team Practice Choose 2 of the Sudoku puzzles you’d like to do.

Deductive Reasoning We have been using deductive reasoning. Deductive reasoning is when you move from things you know or assume to be true - called 'premises' - to conclusions that must follow from them. Premises Conclusion From Ask Dr. Math http://mathforum.org/library/drmath/view/55620.html

Deductive Reasoning The most famous example of deduction is Socrates is a man. All men are mortal. Therefore, Socrates is mortal. The first two statements are premises, and the third statement is a conclusion. By the rules of deduction, if the first two statements are true, the conclusion must be true.

Debrief What do you know understand about the learning target? I can use information to draw conclusions. I can evaluate the conclusions of others. 5/11/10

Ticket Out Kristin said the green square has to be 3. Do you agree with her? Why? Yes! Because 3 is in the first column of the bottom row, 3 cannot be in the first column in another place. So the only place left for 3 is the 2nd row, 2nd column.