Baby Week

We're all prepped and ready for the arrival of our first new family member..

nursery finished... tick
house tidy... tick
bag packed ... tick
classes prepped for next week... tick

baby?? late of course.. just like it's mother.

My wife had a dream that she was having a Labrador. We checked on the ultrasound and it definitely is a baby.

I'll take a day off when it's due and then another four days when they come home. It's all very exciting and we're both looking forward to meeting our new family member. I've been telling my students that we'll name the baby Eunice or Eugene to make sure they grow up a maths dork, study hard, don't get boyfriends/girlfriends until they are at least 40 and make lots of money.

I'm finding the 3A MAT Trig test difficult to construct as my first attempt was too easy. I'll have to beef it up again later.

:-)

Escalating issues with students.

Some teachers are really good at identifying a potential behaviour issue with a student and bopping it on the head. Occassionally a student just gets a bee in their bonnet and won't let it go. What starts as a shoosh directed at a student when I start my lesson, ends with the student on in-school suspension for multiple misdemeaners during the lesson and ongoing issues for months thereafter.

There's a knack for diffusing students and when I'm concentrating usually I can pick the student and prevent them from doing stupid things. My favourite list of things to prevent these events is as follows:

Sleep well: If I'm tired I'm bound to miss the signs of a student ready to blow and probably respond with less patience than I normally would.
Maintain firm class rules: Respect, responsibility, doing your best.
Look for storm clouds: Student body language on entering the room can give an indication to their mood.
Use of humour: Sometimes a simple laugh can turn a student around.
Check their understanding of the topic: If a student feels hopeless they may compensate with poor behaviour to hide the issue.
Low key responses: Have a range of responses that don't draw attention to the student (eg. hand signals, proximity, diversion, interacting with nearby students, sending on an errand.)
Backup responses: Moving students, talking to them out of class, preventing students sitting near disruptive influences, extra homework, class detention.

If all these fail (and the student continues to disrupt the class) or a critical incident occurs (abuse of teacher/student, uncontrollable anger, damage to school equipment, visibly upset/crying) then upline referral is required - probably resulting in suspension. This of course causes further issues (my estimate) is that it takes 4 days to catch up for every day missed in senior school. The quality of the upline support will dictate how easy it is to re-introduce the student to class and resolve the issue.

When suspension occurs I see this as my failure - albeit sometimes I wish I knew some of the 'confidential' information within the school so that I could modify my responses to errant behaviour accordingly.

Rewarding effort of teachers

Today I received a certificate from the Principal in recognition of the summer school run for our 3A maths students and a letter of appreciation from the school. It acknowledged the engagement of students in the summer school programme and recognised the planning required for such an undertaking. Our other two mathematics teachers in the senior school received similar commendations. This is really positive performance management (albeit in normal business it would be accompanied with pay rises or condition benefits). One really negative thing about teaching is that career progression requires entry into management roles and lateral "teaching students" advancement is not really catered to (level 3CT is the one exception and IMHO I haven't met a worthy recipient).

It is nice to put another letter/certificate in my Portfolio!

Now for planning next year's summer school with involvement from schools and students in adjacent areas. It would be great to be able to get some publicity/media attention and for participating students to be able to choose lecture/tutorials based on student needs and interests.

On another front, in the senior school we have a rolling class strategy in year 10 math, where each of the three senior school math teachers take turns following a top year ten class through to year 12. The middle school maths programme (developed last year by the senior school) has made a difference already, with the current year 10 coordinator already noticing that our top students have made solid gains in algebra compared to last year. Our middle school teacher has done well by these kids implementing the programme - a real achievement for the school.

The year 11 3A course is moving along swimmingly thus far. Yay!

Absolute value and the 3A MAT course

Ok. Absolute value - easy enough, to take the absolute value of a number, make it positive if it wasn't already. easy peasy...

... until you start to look at IyI=IxI and ask students to graph it..

... then ask them to find the intersection of Ix-3I=I2x+4I algebraically
... then ask them to find Ix-3I<=I2x+4I

Students really bogged down when they reached inequalities. The approach I used was similar to that by Sadler in his 3A book for MAS. The problem was that I really wasn't sure they understood what they were doing.. they could follow the algorithm but understanding was eluding them.

I started by looking at absolute numbers and explained models for solving using number lines, graphing and algebraically. Then I used a composite approach to assist students visualise what it was they were doing with problems like:

Ix-3I<=I2x+4I

I started by displaying the graph on the board using the overhead gadget for the Classpad.

I entered Graph&Tab from the menu workpane (using the menu icon at the base of the workpane).

I selected Graph&Tab and entered Ix-3I for y1 and I2x+4I for y2. For some reason the graph workpane doesn't allow you to use the 2d tab absolute value option - so use the abs() function under the cat tab in the soft keyboard. When you hit enter it will restore the absolute value notation.

Make sure both y1 and y2 are ticked (if they are not place the cursor on the line using your stylus and hit exe). Hit the graph button in the toolbar (the first icon with the top formula pane selected). The following graph should appear:

We then looked at the original inequality again and I asked what did it really mean?

Ix-3I<=I2x+4I

One way of thinking about it was, "when is the graph y=Ix-3I less than or equal to the graph of y=I2x+4I?"

We looked at the graph and found that the part marked red on the line y=Ix-3I satisfied the inequality.

Using the intersect function under analysis in the menu bar we know that the two lines intersect at -1/3 and -7 therefore the interval is x<=-7, x>=-1/3.

We had discussed that we could also do this algebraically by using the property if IxI=IyI then x=y or x=-y to find the points of intersection.

Eg.

Ix-3I<=I2x+4I

x-3 = 2x+4

-x = 7

x=-7

x-3 = -(2x+4)

x-3=-2x-4

3x=-1

x=-1/3

I then asked students to draw a number line with the intervals marked and substitute the values back into the original inequality. We numbered the three intervals. The first interval represented x<=-7, the second -7<=x<=-1/3 and the last x>=-1/3.

We then selected a value within each of the intervals and substituted them into the inequality. If they were true then this indicated values of x that satisfied the inequality.

Ix-3I<=I2x+4I

Interval 1 (x=-8)

I-8-3I<=I2(-8)+4I

I-11I<=I-12I

11<=-12 (true)

Therefore x<=-7 is a valid interval.

Interval 2 (x=-5)

I-5-3I<=I2(-5)+4I

I-8I<=I-6I

8<=-6 (false)

Therefore -7<=x<=-1/3 is not a valid interval.

Interval 3 (x=0)
I-0-3I<=I2(-0)+4I

I-3I<=I6I

3<=6 (true)

Therefore x>=-1/3 is a valid interval.

The inequality Ix-3I<=I2x+4I is valid over x<=-7, x>=-1/3

Drawing students attention from the graph and back to the algebraic representation released the tension in the room, the screwed up faces and suddenly lights went back on.

Thank goodness!

Here is a link to other CAS calculator posts.