Lord Business Vs. Unikitty

The Activities

  1. Topic: Even and Odd Numbers: Book: Even Steven and Odd Todd by Cristaldi.
  2. Topic: Story problems: The kids had to build a Lego tower to save Batman and Unikitty from Lord Business. They earned Lego bricks by solving the 9 story problems, using Base Ten Blocks.

    My daughter adds the bricks she’s earned to the tower.

    Here are the problems:

    1.  6 Lego friends went to a building party. Each friend brought 5 bricks.  Then 4 more friends came. They forgot to bring bricks. The friends decided to share all the bricks. How many bricks does each friend get?
    2. Wild Style was building a Lego car for Batman. It takes 32 red bricks to build the car. Wild Style only has 19 red bricks. How many more bricks does she need?
    3. Lego cows are built from 3 black bricks and 2 white bricks. A tornado came and smashed a herd of Lego cows.  Emmet found 12 black bricks in the field. How many white blocks did he find?
    4. A Lego ice castle is built from 425 white bricks.  Lego Elsa built 3 ice castles. How many bricks did she use?
    5. Unikitty is building a Lego heart. The heart needs: 1 purple brick, 5 more green bricks than purple bricks, 12 more red bricks than green bricks.  How many bricks does Unikitty need?
    6. Batman, Wild Style, Emmett, and Unikitty are each 4 bricks tall.  How tall are they if they stand on top of each other?
    7. Batman built a Lego house. He used 76 blocks to build half of the roof. How many more blocks does he need to build the rest of the roof?
    8. Unikitty built a Lego school. Each chair took 6 bricks. Each table took 11 bricks. She built 3 chairs and 2 tables. How many bricks did Unikitty use?
    9. A Lego tree is 20 bricks high. A Lego box is 4 bricks high. How many boxes do you have to stack to get to the top of a tree?
  3. Topic: Spacial Reasoning:  Tangrams. The kids used Tangram shapes to form pictures like a Zombie, a Lady, or a Cat.


Lego activity: I drew a cute picture of a cliff with Unikitty and Batman stuck at the top, and I figured out how many Lego bricks it would take to reach from the floor to the top of the cliff. Then I gave the kids 5 bricks for each question they got right, so when they answered all the questions, they could save Unikitty and Batman.

Tangrams: We bought a bunch of Tangram sets from Amazon. Since this is the first time the kids were using Tangrams, I wanted them to be able to arrange the Tangrams on top of the pictures. It turned out to be tough to get Tangram printouts that were the right size, so David used his PowerPoint magic to resize some of the Tangram pictures we found online.  Here are his pictures that worked with our Tangram sets.

How did it go?

Math Circle with 2 kids is so different than with 4 or 5. I actually had time to work with the kids one-on-one here, which was a nice change.  I was hoping the Lego Movie theme would appeal to the one boy in our circle, but it turned out he had never seen the movie :-). The story problems were the perfect difficulty for the two kids.  They could read the problems mostly on their own, and then were able to solve most of them independently either in their head or using the Base Ten Blocks.  The hardest problems were C, D, E, and I.


Tall Towers and Family Trees

The Activities

  1. Topic: Counting by 10s: Book: The Wing Wing Brothers Carnival de Math by Long.
  2. Topic: Spatial Reasoning: Work together to build the tallest possible towers out of Magformers. David and I built our own towers beforehand and marked the heights on the wall.  The kids tried to beat our towers.
  3. Topic: Powers and Charts::  Look at family tree and figure out how many parents, grand-parents, great grand parents each person has.  Also figure out how many kids, grandkids, great-grand kids you’ll have if each person in the tree has 0, 1, 2, 3, or 4 kids.  I drew out family trees of a person’s direct ancestors and descendents. For the descendants I drew several versions of the tree, changing the # of kids each descendant had.

    A direct relations tree where each descendant has 3 kids.


Before Circle, David and I each built magformer towers to give the kids something to try to beat.  I didn’t try too hard, so mine was much lower than David’s.

The family tree charts took awhile to make. I first drew the ancestors half on graph paper. Then I scanned it onto the computer, printed it several times, and drew the various descendant halves. Then I scanned it back in, and printed out several copies for the kids.

How did it go?

There were 3 kids at this week’s circle.  During the summer many families are travelling so we rarely get all 6 together.  All the kids loved the tower building challenge…They had very interesting ideas about how to stabilize their tower when it started to tip.  They wanted to build very large fins on each side, kind of like a rocket ship.

Their tower suddenly collapsed while they were still building it, but they handled the disappointment ok.  Then we had David come in and try to recreate his winning tower, but his crashed suddenly, which might have made the kids feel better.

The family tree activity did not go as well as I’d hoped.  I had filled in a family tree for my daughter with lots of our ancestors (by calling up both grandmothers).  But the kids didn’t seem too interested in the ancestors names.  They did have some fun naming their own kids though. ‘Elsa’ was a popular choice.  Somehow I didn’t get to talk about powers as much as I wanted…the kids didn’t really notice how much faster your descendant tree grows if each person has 4 kids vs 2 kids.

Hands off my donut!


  1. Topic: Fractions and Infinity: Book: The Cat in Numberland by Ekeland, Chapter 5.
  2. Topic: Prime numbers: The kids used blocks to prove which numbers 1-70 are not prime. The easy ones were already done in a previous week. This week they proved 49, 51, 55, 57, 65, and 69 are not prime by making a rectangle out of that many cubes.

    Proof that 51 is not prime. 3 x 17 = 51.

  3. Topic: Logic: 20 questions with numbers. The kids got 7 or 8 guesses to figure out my secret number which is between 1 and 36. They were allowed to ask yes/no questions like: Is it higher than 24? With each wrong guess, a bear would move closer to a picnic treat, and steal it if they didn’t get the number in time.


For the prime number activity, we had a chart with the numbers 1 – 70 taped to the wall. If a kid proves a number is not prime, they get to color in that square on the chart.

For the 20 questions game, I printed out cute clipart of picnic treats like cake, hot dogs, and donuts, and also a cartoon bear. Every time the kids asked a question the bear would move one step closer to one of the treats.

How did it go?

The prime number activity was fascinating. I gave each kid a number of cubes (e.g. 49 or 51) and asked them to prove it was not prime. The kids really don’t have a good search strategy yet, so they would randomly try a rectangle with 2 to a side, and then 5 to a side.  At one point the kid working on 51 tried to make a square out of the blocks. The kid working on 49 saw that and decided to try it.  It worked for 49, but not 51.  There were some inklings of an algorithm…for example, one kid tried a rectangle with 2 to a side, and then another kid suggested they try 3 to a side.

The kids love the number guessing game.  My secret number was between 1 and 36. We’ve played it before, and now most of the kids know that a question like “Is it 5?” is not good. Some of the kids have started to realize that binary search is a good strategy, but the kids are still convinced that whether something is a good question is determined by the answer.  So if someone asked “Is it smaller than 4?”, if the answer was no, the kids would accuse the asker of using a bad question, but if the answer was yes, they would congratulate the asker.