# 71 x 25 = 1230?

## The Activities

1. Topic: Multiplication: Book: 2 X 2 = Boo by Leedy.
2. Topic: Teamwork, Multiplication: As a group, figure out 71 x 25.  If you get it within 100, you get a treasure.

My daughter makes stacks of 71.

3. Topic: Programming:  Do the following programs.
 The functions: Cry { __Do 2 times { ____Print “Wah!” __} } Eat (Box_W, Box_Y) { __Print Box_W __Print “ate” __Print Box_Y } SOS (Box_Y) { __Do Box_Y times { ____Print “Help!” __} }

The programs:

 Print “A ghost cried” Cry Cry Eat(“Avery”, “candy”) Eat(“Arun”, “broccoli”) Print “Joe shouted” SOS(3) Eat(“Laura”, “Poison”) Print “Shelly yelled” SOS(2) Print “Laura was saved!” Eat (“Monsters”, “Lucy”) Print “Lucy said” Cry

## How did it go?

#### 2×2 = Boo!

This book was really fun and clever. The kids really enjoyed it, and laughed throughout it.

#### Big Multiplication

This is a hard problem of teamwork. I decided to step in a bit more than usual, to help amplify good ideas that kids came up with.

Kid A immediately said that everyone should make 25 stacks of 71.  She started doing this, and other kids joined in.  However, the stacks were all over the floor.  After a few minutes of this, Kid A wanted to start trading in 10s for 100s, but Kid B and Kid C both said that wouldn’t work because they wouldn’t know how many stacks they had made.  Kid A then got very distracted and started wandering around, saying she was bored.

Kid D really wanted to count the stacks, but several kids did NOT want her to count until after they had arranged the stacks in rows.  Kid C mentioned that the stacks should be organized, and she started making a line.  Kid B and Kid A meanwhile started making a rows of stacks.  Kid B and Kid C both told everyone it was important that the stacks should not touch.

Eventually they got 25 stacks each with about 71 cubes in them.  Then chaos started.  Kids started complaining that it was too hard to count by 71s. Kid B suggested that they should trade in for hundreds.  Some very haphazard trading ensued, with 10 bars getting mixed in from the extras, and kids taking away 10 ten bars without bringing back a 100 square.

Kid B got a bit frustrated and wanted to quit, but I said we should figure out their answer.  They answered 1230, when the answer was actually 1775.  So they did not earn a treasure.

I told them they’d get one more chance.  Before they started I suggested that they should again make rows of stacks.  And I suggested that all the 100 squares stay on the table. When someone collected 10 ten bars, they should leave the 10 bars on the table and take a 100 square back to the pile.  All 6 kids said they wanted to try again, so they could earn a treasure.

The new problem was 62 * 23.  They immediately started making 23 piles of 62 blocks.  I had to keep reminding various kids what we were doing, and asking if they had any more piles of 62.  This time they assembled the piles and immediately added them to the final rows (keeping the stacks separate).  Soon they had 23 piles. Everyone verified this, and then I reiterated that each person who collected 10 ten bars should trade in for a 100 from the table.

They started to do this, in quite an organized way, except that Kid C was using a 100 square to measure the ten bars (instead of counting out ten of them).  I was pretty sure that she accidentally left behind her measuring square AND added another square to the pile.  I pointed this out, but she thought it was ok.

Kid B took over the singles, and traded them in for 10 bars.

Then they started counting the 100s.  They got to 1200, 1300, 1400…and there was one more…but Kid A suddenly said “No, this one doesn’t belong, because it was Kid C’s measuring square!” and took it out.  The other kids let her, and their final answer was 1436. The correct answer was 1426, so they celebrated their victory, and then helped pick up.

I asked Kid A how she knew to take out that 100 square, and she came up with a variety of somewhat strange reasons, like “I knew it should be smaller than our last one, so I took one out.”  I suspect she either saw the answer somehow, or saw my face when I realized they had one too many hundred square.

#### Programming

We had new functions and new programs this week.  Kid A missed last week, so she didn’t yet know about functions.  Three of the kids were able to independently do almost all the programs, and enjoyed reading the silly sentences.  My daughter was again super-focused and zoomed through.  She was often waiting for me to hand her the next program. The only thing that tripped up her was the SOS function.  She didn’t understand how to “Do Box_X times”

Kid D was doing ok on the programs.  However, she lagged behind quite a bit and was distracted, drawing on her sheet.  Perhaps the time-change had put her in a weird mood.

I helped Kid A quite a bit.  She remembered what “Print” meant, but she didn’t initially understand the functions (since she had missed that circle).  After some help from me, she solved 3 of the problems…but I’m not completely sure if she was just pattern matching or actually following the commands.

Kid E got very frustrated on the first program.  The other 4 kids finished before her, and then she started to doubt herself.  I came over to help, but she started to cry, so I asked if she wanted a break. Her dad noticed and came over to help her trace through.  After a bit more frustration, she started to make progress again, and solved 4 of the problems.  She’s just not quite comfortable with the functions yet (she wanted to write “Cry” instead of execute the commands in the Cry function, which was the same problem she’d had last week).  It was also extra noisy this week which didn’t help.

Hopefully we can get all 6 kids to the point where they are comfortable with functions and loops.  Then we can try having the kids write their own programs.  There is lots of good logic in programming.