__: 6.15 Measures of Central Tendency__

**SOLs Covered**__: (26) Measures of Center__

**Math Dictionary Sections**__:"You Can Do It!" Quiz #2 (Fri. 4/20); Graphing & Quadrilaterals Combo Quiz (Thurs. 4/26)__

**Upcoming Assessments**The always hectic week before Spring Break saw us wrapping up our unit on the measures of central tendency. We spent more time highlighting the major differences that middle school math brings for each of the measures. In elementary school, students were used to

**median**being a little simpler by having exactly one number in the middle of a data set that has an odd number of pieces. Sixth grade math has students finding the median when given an even number of items within a data set that thus leaves two numbers in the middle, which requires finding the average of the two numbers or even plotting the numbers on a number line to determine what point would be halfway between the two. The other complication students run into when finding the median is forgetting to put the numbers in numerical order, though this isn't necessarily a new problem. For**mode**, students are now dealing with data sets that have three possibilities instead of the one or two they're used to from previous years. They are finding that instead of having one obvious number occurring more than the others, there are times the data set has no mode (which they might have seen in elementary) or even two modes (aka bimodal).The students found these changes were fairly easy to handle, however the new way of "looking" at

**mean**took a little bit of time (and Skittles®!) for the students to grasp. The same "old rules" and definitions still apply, but we now also refer to mean as the**"balance point"**in a data set, a point on a number line where the data distribution is balanced. The distance (spaces) of all the points below the mean (on the left) corresponds and balances with the distance of all the points above the mean (on the right). I compare it to a see-saw that is evenly weighted/balanced on both sides so it doesn't tip in either direction. To illustrate the concept further, we worked did an activity with Skittles® in the "fun size" packs that had all the students counting the number of candies in their bags. Once everyone finished their counting (and eating!), students wrote their numbers on sticky notes and placing the notes onto a number line drawn on the board in order to create a line plot. We "guessed" where the numbers should be balanced based on the visual (often where most of the numbers were clustered) and then checked by counting the number of spaces for each point to the left, then to the right of our "guessed point." In each class, we found we didn't have a perfectly balanced data set with our guessed number, though our hypotheses were very close each time, especially when we calculated and compared to the "old school" mean. The students were then asked to determine what possible numbers would be needed, in theory from unopened bags, to have the balance point where we wanted it to be. The activity as a whole, which included several other examples, really helped the students understand this new meaning.The week ended with two quizzes, the Measures of Central Tendency Quiz on Wednesday and the first "You Can Do It!" Quiz on Thursday. The "You Can Do It!" Quizzes when combined equal one Math 6 simulation SOL test. A letter further detailing the quizzes will be sent home after the break since will be in "review-mode" at that point in preparation for the SOL test. There are still a few new topics we need to cover, but a portion of every week will be spent preparing for the big test. Students have been asked to bring in two 3-pronged folders when they return from break, which will be used to house our review materials. Students will be reminded, but they'll be able to receive some of the packets early if they bring them in immediately.

Yesterday we got word from DimensionU the 2012 "DU the Math National Scholarship Tournament" will begin this Monday, April 9th. Running through May 13th, students with the highest number of correct answers per week can compete for their chance at weekly prizes and could ultimately earn a chance to compete for one of for college scholarships in the final round: one $25,000 scholarship and three $5000 scholarships. Chesterfield students have been provided with an account by the county but must register at DUtheMath.com to qualify for the tournament. Use your username (CH+StudentID#) and password to register. Flyers can be downloaded from Edline for further information. I highly encourage students to participate not only for the chance to win awesome prizes but also for the huge academic benefits. The game is a great way to practice and review everything we've covered this year and will jump-start each student's personal SOL review.

Happy Easter!!! Happy Gaming!!! Happy Spring Break!!! Stay safe and enjoy the free time!!!

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