# Friday, June 16

Hi All —

In class this week students have been working on their statistics project. The project asks them to analyze a question in statistics — either a question which I created from a data set of student height and gender in CPMS advisory classes or a question of their choosing with data they find or generate. Here is the project task sheets and rubric.

Statistics project is due on Tuesday.

# Thursday, June 8

Assignment 9.4 Task + RSG. In class notes on standard deviation

Note: The formula for standard deviation involves $\dpi{300}\inline \Sigma$ (Greek, "Sigma") or "sum" notation. $\dpi{300}\inline x_i$ refers to the ith element in the data set, $\dpi{300}\inline \overline{x}$ is the mean x-value.

$\dpi{300}\inline SD = \sqrt{\dfrac{\sum_{i=1}^{N}(x_i - \overline{x})^2}{N}}$

1. Find the difference between each value and the mean

$\dpi{300}\inline (x_i - \overline{x})$

2. Square those differences

$\dpi{300}\inline (x_i - \overline{x})^2$

3. Find the sum of all of the squares

$\dpi{300}\inline \sum_{i=1}^{N}(x_i - \overline{x})^2$

4. Divide that value by N (the number of data elements in the set)

$\dpi{300}\inline \dfrac{\sum_{i=1}^{N}(x_i - \overline{x})^2}{N}$

5. The Standard Deviation is the square root of the result

$\dpi{300}\inline SD = \sqrt{\dfrac{\sum_{i=1}^{N}(x_i - \overline{x})^2}{N}}$

One way to understand the standard deviation is that it is kind of like the average distance from the mean in the data set.

# Wednesday, June 7 + Facial Tissue request :)

In class we have started Module 9 which is about data and statistics. Today students are completing 9.3 Task and Ready Set Go. We have completed 9.1 and 9.2 as well as a "3 Chips" Problem write-up that was turned in today at the start of class.

The class has run out of facial tissue but there are still plenty of sniffles. So, if you would like to donate some facial tissue to the class that would be much appreciated and put to good use, keeping kids in class instead of heading to the restroom. Thank you thank you thank you!

# Wednesday, May 24

We are finished with Module 8. Today we spent class time reviewing Module 8 skills. There is a test covering

* The distance formula  (section 8.1)

* Using coordinates to prove that segments are congruent, parallel or perpendicular (8.2)

* Using congruence, perpendicularity and parallel properties to justify conjectures about shapes. (8.3)

* Writing and analyzing vertical shifts in linear or exponential functions (these have the form f(x) = g(x) + k).

Past assignments

Friday — 8.4 Task + Go (in class) completed on whiteboards, not necessarily in notebook.

Monday — 8.5 Task + RSG

Tuesday — 8.6 Task (Part 1/2/3 all) + 8.6 Set

Today’s assignment: Algebra & Geometry Review worksheet

# Thursday, May 18

Today's class. Review of 8.3 distance problems, graphing video activity, no hw.

# Wednesday, May 17

These problems deal with proving congruence, perpendicularity, and parallelism using coordinate relationships. So for example, showing that the shape below is a rectangle by demonstrating that the slope of each pair of adjacent sides is perpendicular. We demonstrate perpendicularity by computing the slopes of the lines say slope(BC) = -(2/6) = -1/3 and the slope(AB) = 3/1 = 3. Since -1/3 and 3 are negative reciprocals we can see that sides AB and BC are perpendicular, and thus the angle at B is a right angle.

# Tuesday, May 16

In class many students were absent due to WEB training. We worked in groups to complete 8.2 Task + RSG.

# Monday, May 15

In class students worked through problems intended to help them create the distance formula

$\dpi{300}\inline d^2 = (x_1 - x_2)^2 + (y_1 - y_2)^2$

which becomes

$\dpi{300}\inline d = \sqrt{(x_1 - x_2)^2 + (y_1 - y_2)^2}$

They should understand how and why the formula works. And also see the relationship between the distance formula and the pythagorean theorem which it is based on

a triangle is right if and only if (its sides a, b and c) satisfy $\dpi{300}\inline a^2 + b^2 = c^2$

# , Tuesday, May 9

In class: we worked through and discussed a practice SBAC test. Tomorrow students will be completing the Performance Task.

All 8th grade students are to bring their chromebook to class charged and ready for testing. No cell phones or internet device use allowed during testing sessions even if you are done.

Assignment: AGS students should be working to complete their Module 7 assessment which is still due at the start of class on Friday. So, at this point anything they have not completed should be completed at home. I would recommend completing problems 1 – 4 by tomorrow. And then completing #5 tomorrow evening.

# Monday, May 8

In class: students had time to work on the Module 7 assessment. We reviewed the expectations and rubric.

Assignment: in order to be on track to finish by Friday, tonight students should complete all of problems 1 and 2 (there are 3 parts of #1). These problems require students to explain their thinking, use geometric vocabulary, label diagrams with appropriate congruence and measurement marks, and be precise.