Sunday, August 29, 2010

Decimal Point

Linguists have issues with grammar in every day life just as I have issues with the decimal point.  I can't begin to count how many times I see a store marking an item with 0.50¢.  I make sure to have the decimal point discussion with students some time in the year.  After the decimal point talk, most students catch onto the fact that if stores mark an item for 0.50¢ then we should be able to grab two of the items for a penny.  Of course it is either $0.50 or 50¢.

The other day in Sam's Club I saw a new one that caught me off guard.... Churros for $0.50¢ I am not sure what to make of both symbols at once.

Mega Posters

In my classroom last year I decided to try making a block poster.  The concept is simple... upload an image and select the size of the Block Poster and it prints the image on mulitple sheets of paper.   One problem is the amount of ink it can use up, but if you get a good image you like, it can make for a nice image on the classroom wall.  I tried adding a quote at the top of a nice looking picture, but realized I should have made the letters even larger to stand out. 

This year one of the quotes I printed out at and put on my wall, some of the students informed me I spelled Intelligently incorrect... they had a good LOL (I later added the 'l' with a black marker).


Sunday, August 22, 2010

Departmentalizing Math

In education we departmentalize teaching multiplication of decimals, then percents, then adding fractions, then dividing fractions....  By the time we have moved onto prime factorization the average student has forgotten how to find 15% of 30.  There are many strategies such as reviewing, warm ups, spiraling that can help.  One of many teaching strategies of not compartmentalizing math is KRYPTO.      Putting 4 random digits on the board such as 5  0  7  4 can keep students reaching for new methods mixed with old.  Just because factorials are not taught in 6th grade does not mean students shouldn't be introduced. The more strategies you learn the more  chance you have of success (for example 4 divided by .5 equals 8 confuses students but being able to use it as a "weapon" in KRYPTO empowers the student), not to mention KRYTO is endless (using a little creativity and math knowledge 0 0 0 0 can even be done) and can teach the rule attributed to various chinese philosophers, "The journey of a thousand miles begins with one step" or perhaps "The journey of a thousand KRYPTO's begins with ones first attempt".

KRYPTO Rules:  You must use all 4 numbers only once and any mathematical symbols and letters are fair game.  I tell my students that  a math teacher walked in they must be able to evaluate the expression equal to 15, and of course 3 + 5 + 8 - 1 is the same as 5 + 3 + 8 - 1 of course this is a good teaching opportunity to discuss the commutative property.

Here are some answers to 5   0   7  4 can you find more?