John's Scribepost for December 5th,2010

Sup guys today in class we talked about scale and scale factors.
The first thing we did was this:

Scale : Proportional Reasoning

Image : Actual

Then we did a problem is was:

A B Aprime Bprime
1 : 7 X : 23.5

But before starting with the question Mr.Backe
explained something about where the primes should go and where they shouldn't go.

Works: A/Aprime = B/Bprime

Doesn't Work: A/Aprime = Bprime/A

Then we started on the question

1 : 7 x : 23.5

1/x = 7/23.5 so you would cross multiply the numbers so 7 multiply x equals 7x
so you would put it like this.

7x/7 = 23.5/7 then 7x/7 would cancel each other out so you would divide 23.5 by 7 and your answer will be 3.36
X=3.36

After we were done talking about that question we did another

2 : 3 11 : x

2/3 = 11/x so as the last question went you would multiply 2 by x which would equal 2x and 3 by 11 which would equal 33. So the format would be like this

2x/2 = 33/2

2x/2 would cancel each other out and you have to divide 33 by 2 to get your answer of 16.5.
X=16.5 Mr.Backe said it was called By Inspection.

After finishing more questions we reviewed the

mm cm dm dam hm km
mi ci di 1000 deca heca kilo
1000000 10000 m 100 10 1
100000 l
g

Then Mr.Backe asked how many 1cm would you need to reach 10km and the answer was you would need 100000 1cm to get the 10km.

Then Class Ended.

Homework:
Read 4.2 139-142
do SYK
CYU 1-3
Practise: odd or even
Apply: 13-16 or 15-19
Extend: 20 and 21 or 21 and 22 (you have to do 21 for sure)

TEST ON WENSDAY ON SCALE AND SCALE FACTOR

If I got anything wrong tell me so I can fix it!!!

JOHN!

John's Scribe Post For November 4th, 2010

Hey guys

Last class Mr.Backe assigned me question 24 in section 2.1 page 58.

Question: Give an example of a fraction in lowest terms that satisfies the following conditions.

A) Greater then 0, with the denominator greater than the numerator.

Answers: 1/3 or 2/5

B) Between 0 and -1, with the denominator less then the numerator.

Answer: for this answer I had a really hard time with so I looked at the back of the book. 3/-4

C) Less than -2, with the numerator less than the denominator.

Answer: -8/4

D) Between -1.2 and -1.3, with the numerator than the denominator.

Answer: 4/-3.

If anyone can explain question B it would help and if I got anything wrong tell me.

-JOHN!

John's Scribe Post Part 2

So the second part is the cylinder on page 31 were we had to calculate the area so in the picture below shows you the Diameter and radius:
This is what the cylinder looks like spread out, this is the out side of the cylinder.

This is the inside of the cylinder.

Then Mr.Backe wrote this down 

2(pie r² big-pie r² small)

 2(pie 10² - pie 5²)

                                                                                  2(pie 5²)
                                                                                  2(pie)(25) 

                                                                                  = 157.1

so thats it I think if anything is wrong tell me because I have to fix it.

Homework is TUTPUP, Apply and Practise 4-9 

-John! and I pick Paulo for the next scribepost.

John's Scribe Post for October 4th, 2010

Sup guys so today in math class Mr.Backe asked us if we did Check Your Understanding on page 31. No one did it so we did the problem together. First Mr.Backe drew the cake like this one:

So Mr.Backe told us to draw the top view. Then he asked me what happens to the circle on top. So I said that it blends in with the square part of the cake.

Then we had to draw the side view which is the one you see in the bottom picture:

So the reason why I have 20 cm d is because to find the circumference you need Pie D(diameter)

so to get the surface area Mr.Backe wrote the answer down so here it is:

S.A.= 25²+5 pie 20+4(25)(5)

       = 625 + 314.2 + 500

       = 1439.2 cm²