<![CDATA[Alveyworld Inc. - Exploring Computer Science]]>Sun, 21 Jul 2024 07:36:16 -0700Weebly<![CDATA[Scratch Lessons]]>Wed, 12 Nov 2014 15:45:11 GMThttp://alveyworld.pineview.org/exploring-computer-science1/scratch-lessonsWe have been having fun learning the basics of programming in scratch with lots of fun little projects.
Here is the alveyworld studio where we are putting all our best stuff:     http://scratch.mit.edu/studios/620382/

baseball.sb
File Size: 128 kb
File Type: sb
Download File
name.sb
File Size: 11 kb
File Type: sb
Download File
alphabet_learning.sb
File Size: 9 kb
File Type: sb
Download File
summer.sb
File Size: 1969 kb
File Type: sb
Download File
cat_story.sb
File Size: 1248 kb
File Type: sb
Download File
moving.sb
File Size: 79 kb
File Type: sb
Download File
variable_example.sb
File Size: 27 kb
File Type: sb
Download File
]]><![CDATA[Sorting: Divide and Conquer]]>Fri, 03 Oct 2014 16:23:31 GMThttp://alveyworld.pineview.org/exploring-computer-science1/sorting-divide-and-conquer
Last time we learned that searching algorithms depend on the data being sorted. So we need to learn how to sort things efficiently.

Today we learned a few basic sorting algorithms for putting things in order. We tried putting paper bags at random weights in order of lightest to heaviest using a simple scale that compared the weight of two bags.

We learned that if we divide the problem in half repeatedly using a Quick sort  algorithm it was much more efficient than always finding the lightest bag which is called Selection sort.

We also had fun emptying the bags, but I am not sure where all the starbursts went?
]]><![CDATA[Binary Searching (or Divide and Conquer)]]>Wed, 01 Oct 2014 17:01:36 GMThttp://alveyworld.pineview.org/exploring-computer-science1/binary-searching-or-divide-and-conquerPicture
Today we built towers for Donald Trump with legos. We tried to build them as efficiently as possible. Some of the groups took 39 weeks to build the tower and some were more efficient. One group only took 6 weeks.

We also looked at algorithms for searching and finding a word in the dictionary. First we tried to start at the beginning at turn each page until we found the word. This is a Linear Search, and it wasn't the most effect method, it took 700 page turns to find the word Walrus. If we divided the book in half each time we could find any word in a 1500 page dictionary in 6 or 7 page turns. That is what we call a Binary Search, where we cut the problem in half each time. That was much more efficient.

But we also learned that the Binary Search only works when the data is sorted, so sometimes you are stuck with the Linear Search.
How many different applications can you think of for the Binary Search where we solve the problem by cutting the problem in half each time?
]]><![CDATA[Counting in Binary]]>Mon, 29 Sep 2014 16:30:52 GMThttp://alveyworld.pineview.org/exploring-computer-science1/counting-in-binaryToday we learned how to count in binary using cards with dots on them. 
Picture
Each card represents a binary digit that can be a 1 or a 0. The card is a 1 if the dots are showing and the card is a 0 if they are hidden. To convert a binary number to regular numbers just add up all the dots.

Examples: 
00000 -> 0 + 0 + 0 + 0 +0 = 0
00001 -> 0 + 0 + 0 + 0 + 1 = 1
01010 -> 0 + 8 + 0 + 2 + 0 = 10
10100 -> 16 + 0 + 4 + 0 + 0 = 20
11111 -> 16 + 8 + 4 + 2 + 0 = 31

We also did a magic trick where I read peoples minds, if you want to make the cards to impress your friends at dinner parties here is the instructions

Then we learned how to count binary on our fingers (be careful not to be rude).
Counting to ten in binary:
1
10
11
100
101
110
111
1000
1001
1010
]]><![CDATA[Understanding the problem]]>Thu, 25 Sep 2014 16:43:56 GMThttp://alveyworld.pineview.org/exploring-computer-science1/understanding-the-problemToday we had a problem to solve. We needed to design a new cornrow hair style for Lebron James for his first game as a new Cleveland Cavalier. But we first had to study about what cornrows are and the historical significance of the culture of cornrows and how to apply the patterns. We found that cornrows are rich with symbolism and the origins of cornrow hair styles go deep into African culture. (read about it here: http://csdt.rpi.edu/african/CORNROW_CURVES/culture/african.origins.htm)


We used the software from http://csdt.rpi.edu/african/CORNROW_CURVES/cornrow_software/cornrow_software.html
to plan and implement our designs for Lebron's new hair style. Here is one example:
Picture
]]>