Monday, March 31, 2014

Brain Break: Sudoku and KenKen Puzzles

We have been working SO hard to finish third quarter in Math Workshop.  With CGA 3 behind us and FCAT ahead, who needs a little brain break?  In December, I taught the students how to do Sudoku puzzles (we started with "light and easy" 4x4 puzzles).  These puzzles are excellent for developing logic skills, which are essential for critical thinking in problem solving (and they are fun!).

Light and Easy 4x4 Sukoku puzzle
 
Traditional 9x9 Sudoku puzzle
These addictive puzzles are great for rainy days and long rides!

This weekend, I discovered KenKen puzzles, which are related to Sudoku puzzles.   

Today I showed the students how these puzzles work.  There are also free KenKen apps (I use Ken Ken II).


As a math teacher, KenKen puzzles interest me because they are a fun way to practice basic fact operations.  Be forewarned, they are very addictive (there's a timer you can turn on or off), especially if you are competitive like me!  My best time on a 3x3 KenKen puzzle was 14 seconds.  Can you beat my time?  :-)

Thursday, March 6, 2014

Area & A Mathematical Milestone

This week, we started our first geometry unit, Area.

We've learned that area is the number of units needed to cover a shape.  Since square units are easiest to cover most shapes and count,  we usually use these to measure a shape's area.

Today we broke out the GeoBoards and learned how to use them as tools for modeling area and other two-dimensional shapes.

(First, we had 5 minutes to "explore" our new tools, be creative, and use them as toys.  Naturally, this lead to a nice review/discussion about symmetry!)

Next, we made a grid on the GeoBoards and found out each board has an area of 16 square units.
From their work with arrays in third and fourth grades, the students have realized they don't need to count squares for rectangles one by one. (Yes, a square is a rectangle!)  Instead, we can multiply the dimensions (number of rows times number of squares in each row).  Knowing this, the students learned their first mathematical formula:

Area of a rectangle = Length x Width

Then we practiced making shapes with a given area--2 square units, 3 square units, and 6 square units.
Some students remembered from third/fourth grade fractions that two triangles are equivalent to one square unit of area and used them in their designs.

I don't even think some of the students realized it was raining outside and recess time.  :-)