# Staying Late for Sudokus

## The Activities

1. Topic: Money, Addition: Book: Pigs Will Be Pigs by Axelrod. This book is about a family of pigs that hunt through their house for money to go to out to eat for dinner.
2. Topic: Programming: First, work together with me to trace a program:
 Box_X = 10 Print “I can count backwards!” Do 10 Times { ___Print Box_X ___Box_X = Box_X – 1 } Print “All done!”

Next the kids had to write their own programs:

1. Write a program that prints: “The witch laughed Ha Ha Ha Ha Ha Ha Ha”
2. Write a program that prints: “Happy Happy Happy Happy Birthday to You!”
3. Write a program that prints “2 4 6 8 10 12 14 16 18 20”

One student’s solutions to the programming questions.

3. Topic: Logic, Puzzles, Sudoku: I handed out a separate Unifix Soduku puzzle to each kid.  I have 500 Unifix Cubes, so it was enough for all the kids to do their own puzzle.

## How did it go?

We had all 6 kids at circle this week, it was a loud, rambunctious, but happy circle.

#### Pigs Will Be Pigs

I had enough paper money and coins that we could make a stack of all the money that the pigs found in the book.  The kids were all excited to handle real money.  The book does not say how much total money the pigs had, so the kids added up our big stack and found 34.67, which matches the amount in the back of the book.

We also figured out how much money the pigs spent: \$7.99 * 4.  Two kids suggested multiplying 8 by 4, and then subtracting 4 cents, so that’s what we did.  I’m not sure if all the other kids understood why that would work.

At this point, the kids were getting restless, so I skipped the last question, which is how much money did the pigs have left after they ate.

#### Programming

At the start of this activity I reviewed what had happened last time.  All the kids agreed that if something is too hard, they should keep trying and not give up or cry.

I started by tracing through the above program with all the kids. I really emphasized the start and end of the loop, since several kids had been unsure which lines were part of the loop.  I went around the circle asking each kid what the next line did and where the program went next.  By the end of this, all the kids seemed to understand the loop, even the two kids who had struggled with this in the past.

Next I handed out paper and pencil to write answers to the Happy Birthday program.  One kid finished first.  Their program was: “Happy Happy Happy Happy Birthday”.  I pointed out that the program did not tell the computer what to do with those words, so the kid changed it to “Print ‘Happy Happy Happy Happy Birthday'”.  That worked, so I challenged the kid to solve the same program with a loop, which they did after a few tries and a couple syntax corrections.

The other kids successfully wrote the loops with minor syntax problems. No one got too upset when I asked them to fix their programs.

The Witch program was also easy for most of the kids, though one girl initially wrote a program that printed “Ha ha ha ha laughed the witch”.

I then handed out the 2 4 6 8 10 program, and said it was a bonus problem, so it’s ok if you don’t get it right.  Eventually 4 of the 6 kids did successfully solve it, with a loop. Almost all of them had a few corrections before getting it quite right. Interestingly, they all figured out that they should add 2 to X each time.

#### Sudoku

The kids all loved the Unifix cubes.  Some had seen Sudoku’s before, and some hadn’t.  I started going around to each kid to help with their puzzle.  Some kids tried to just put blocks down and adjust the placements if the puzzle didn’t work.  I encouraged them to instead keep track of the possible colors, but putting a stack of blocks on the square.

At the end of circle, the kids did not want to stop working on their puzzles, so all the parents came in to try to help their kids.  These 6-color Sudokus are actually pretty challenging, so even with a parents help many kids didn’t finish.  However, it seemed like all the kids like the puzzle, so we’ll try it again.  Next time I’ll probably work through one whole puzzle while the kids watch, before I hand out individual puzzles.