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Old 10-18-2011, 06:50 AM  
DamianJ
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Accuracy of blackboards in 'school' porn



2x + 3 = 9

x = /2 [or 12?]

Mathematics - simple algebra.

The handwriting is large and generally clear, even though this class appears to only have one student in it, and he sits at the very front. It might be worth advising the student to have his eyes tested if he is unable to read smaller text at this distance. Remember that poor learning may be as a result of poor vision - the student might not even be aware that he has a problem. If the teacher does keep her handwriting that size she will have to get a bigger whiteboard when she starts doing quadratic equations. Finally, when writing algebraic equations, it is preferable to do a more cursive x for the unknown symbol, to avoid confusion with a multiplication sign.

Unfortunately, the answer is unclearly written - is it 2? 12? 1/2? Whichever of these it is meant to be, it is wrong. Here is the correct calculation:


2x + 3 = 9

Subtract 3 from both sides:
2x = 6

Divide both sides by 2:
x = 3

Given the differences in handwriting in the '2's though, it is possible that the teacher left the answer blank for the student to fill in, and is pointing for him to return to his desk. Either way, it is better to show one's working, so that if an error is made, but followed by correct calculations, the examiner may still give marks for the later parts of the answer, even if incorrect.

5/10 - could do better.




1. S=0 A=0
2. S=1/4 A=1/16
3. S=1/2 A=1/4
4. S=1 A=1
5. S=2 A=4
6. S=3 A=9

Mathematics
t p
m
n
3/4 02/5
100=S=A
A
S 42/A9

Mathematics - year 8 level

This sets out to be a good illustration of the function more commonly expressed as y=x2. (Why the teacher has chosen A and S is unclear; these are sometimes used in lower case form as acceleration and distance respectively, but the relationship between them would not then be physically correct.) The important points (S=0, S=1, two points where S<1 and two points where S>1) have been well chosen to illustrate this function, though it would have been useful to have included some more points where S<0 to show what happens when squaring a negative number.

The graph has then been plotted, but sadly this is where the lesson begins to falter. Firstly, axes on the graph should be labelled with 'S' (horizontal) and 'A' (vertical). And the graph that has actually been plotted seems to be more like:
1. S=0 A=4
2. S=4 A=8
3. S=6 A=15

The graph is roughly the correct shape, but is not positioned correctly: it clearly intersects with the vertical axis at A=4. Even allowing for other drawing errors, this is a function more like A=bS2+4. It would also have been useful to extend the graph to S<0.

What is going on on the right-hand blackboard is less clear. There is a drawing of a trapezium, and also the equation 100=S=A, which is hopefully not meant to be related to the function A=S2.

Finally, the teacher should make sure that her students keep their focus on their work. She only has three students, so can't complain too much about the pupil-teacher ratio. The teacher is giving all her attention to the lone male student, allowing the two female students to talk to each other, thus reinforcing gender stereotypes of women in maths, despite being female herself. Sadly, it is this kind of attitude which leads to the 'Math class is tough' talking Barbie and low numbers of women choosing to study maths in further and higher education.

5/10 Shows some promise



lots more:
http://blackboardsinporn.blogspot.com/
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