Monday, June 20, 2011

Standard Devi-what? (1512)


As a “non-traditional” student, it is hard to remember how and when I learned some of the basic information in math class. I might have some visions of a chalkboard and a teacher lecturing, others might have memories of endless sheets of problems to be solved. The methods we learned many years ago might have changed for the current generation of students, and we must adjust and learn how to teach these children.

I have not used standard deviation in years and struggled while recently trying to calculate it. I started with things that I could do well, like calculating the mean of the items. After finding the mean in the set of numbers, I then subtracted the mean from each number in the set. This gave me the deviation of the specific numbers from the mean. The next steps are to square all of those deviations (differences) and add them together and then divide by the count to get the variance. (Is anyone else tired and confused by this point already?) Once you have the variance you are so close!! Keep going!! The standard deviation is computed by taking the square root of the variance.

The standard deviation is a way of knowing what is normal, and what is extra large or extra small. The standard deviation can either be negative or positive depending on whether it is smaller or greater than the mean. It is a difficult concept to understand, to say the least. I could have used this knowledge more this past year when the preschool screeners were trying to tell me where my son was compared to others who had tested. I was quite confused and couldn’t remember the reasoning behind the term and was too afraid to ask in fear of looking like an idiot. I’m glad that I can now understand the concept and inform future parents on the explanations behind the scores they might see.

Here is a website that walks you through the steps to compute the standard deviation.

What is a map, and why do I need to know how to read it? (1512)


With our current technology wants/needs and endless electronic devices, will road maps become a thing of the past? When I was reviewing information on proportions and scale drawings I became more interested in this age old concept of how to determine “are we there yet?” that every child will probably ask at some point this summer. Sure, it is easy to look at our Garmin, Tom-Tom or iPhone and read what it has to say, but does that really cause us to think about how far it is?

I can remember as a child opening up the dusty 2 foot high atlas with all of the states listed in alphabetical order and find it quite interesting to see different points within our state, and other states I dreamed about visiting. I’m sure that most elementary students would not know what the little legend words and symbols mean and how to transfer that 1 inch equals 50 miles, for example. Would they know what the list of cities and numbers also means? I loved looking at how many miles Minneapolis was from Brainerd and thinking about how far it really meant by comparing to the miles between St. Cloud and Brainerd.

I don’t remember how we ever got so interested or consumed in just dreaming of things within that atlas, but with 4 kids in the family, there were many times we were fighting over this neat treasure. I hope to continue this with my own children and within the classroom. I think that a teacher would need to adjust things to the age level information that they can follow. For instance, when we drive to Montana next year to see my sister, I will place a big cow on the map near New Salem, North Dakota so they can see it on the map and on the horizon!

Fractions and proportions might seem scary to most of us, but when you look at the relevance it has to our every day life it should seem worth the effort to learn it before reaching for an electronic toy to solve our problems!

Here is a good website that walks through the age appropriate levels with using a map. 

Is it a union or intersection? (1510)

I was having some issues with getting my symbols to show up when I pasted from word, so I found a way to embed a pdf file at the link below. So please clink on this information to view my blog, and let me know if you have any great ideas on how to insert symbols for union and intersection of two sets!

Union and Intersect

Here is a YouTube video that also explained the differences quite well.

If-Then (Week 1, 1510)

After a 10-year break from college courses, high school calculus, geometry, algebra and basic elementary math, I'm back at it! What I have realized while diving back into the content is that I remember bits and pieces of the information. I was not able to complete any of the questions without referencing my textbook, at first. I wonder if this is what young children feel like after returning from summer break and staring at their math homework that they had mastered only 90 days prior? 

Part of the difficulty I experienced was due to the terminology being something that I don't use in my every day life. There are not many people I know that analyze a conditional statement for "fun". I have noticed that my 4-year-old son often has troubles with if-then scenarios, but I guess I can't blame him when I struggle at times too! He doesn’t always understand the phrase, “If you go to the bathroom and wash your hands, then we can go to the park.” He immediately rushes out the door without thinking twice about any of the steps in between that might need to happen. Sometimes we just need to stop and think about whether a statement makes sense or whether it has any instances where the answer would disprove the statement.

A friend who was struggling with the terms and explanations related to reasoning mathematically was directed to this link (and shared it with me) and it is a wonderful video to engage anyone who wants to learn about this topic! If-then statements are everywhere and it is nice to have a real world explanation versus a textbook for examples.




More about Laura.....

I previously graduated from Bemidji State University with a degree in accounting in 2001. After working in an office the past 9 years, I realized that it was time to make a difference in the world. I spent quite a bit of time in my daughter’s kindergarten class this year, and I was hooked on becoming a teacher.

I love numbers and the problem solving that goes along with math. I plan to have my math endorsement when I graduate. My goal is to make math fun and interesting for my students so they WANT to learn more instead of dreading that hour of the day. When you combine real life examples with the principles of mathematics, it makes the information easier to comprehend.