Showing posts with label robby's scribepost. Show all posts
Showing posts with label robby's scribepost. Show all posts

Monday, May 5, 2008

Robby's Scribe

Collecting Like Terms
Like terms are Terms that have the same Variables next to them. Variables are letters that stand for unknown or given numbers. Like terms are 2 or more terms that can be combined to simplify the equation. Lets look at an example:






This right now is an algebraic math sentence. In algebra, you don't always have to find an answer to the question, that is, if you aren't told what the variable stands for. This is one of those occasions.
In algebra, you don't use all the operators you would use for non-algebraic equations. Like, for example, times (x). Because times has a operator that looks like a variable, it gets confusing (Like so: Variable x X x = x ...no it's not what you were thinking). So they removed it (they being those math geniuses that invented algebra). Instead of writing 5 x (x+2), you remove the x and assume its multiplication. And when multiplying a number with a variable, you write them next to each other (5x). This becomes a Term.

Back to the math sentence in blue above. An easy way when multiplying things in brackets and theres a variable in there is to multiply the outside number with the variable. So it would look something like this:







Like I said before, when multiplying a number with a variable, you put the variable on the right side of the number and it becomes a term. So 5x means Five groups of variable x.

The next part of the question is the +2. You would read this as positive two, because in algebra, you deal with integer numbers a lot. Now you have to multiply it with 5 now, because its still in the brackets, and if there's no operator between the brackets and number on the outside, you assume its multiplication.








Now, we multiply the 5 with the 2. 5 x 2 = 10 (note, I used the x symbol for multiplying because we aren't multiplying the terms, and this equation won't go in the final answer, only the 10 will)
The math sentence now looks like this:






This is a proper algebraic sentence. The terms should always be on the left side, and the non-terms, or integers, on the right. Now to to show you how to write this question using algebra tiles. But first, look at the different kind of shapes used to represent the parts of a algebraic-math sentence.




















Now that we know what shapes I'll be using mean, on with the algebra-sentence. I'll simply show what the simplified answer to the algebra sentence near the middle of my scribe-post looks like with algebra tiles...





=

Tuesday, March 18, 2008

Robby's Scribe


Pythagorean Theorem: Problem A
You are locked out of your house and the only open window is on the second floor, 25 feet above the ground. You need to borrow a ladder from one of your neighbors. There's a bush along the edge of the house, so you'll have to place the ladder 10 feet from the house. What length of ladder do you need to reach the window?
In this picture I made of the problem, the bushes were removed, but we still have to solve the problem.
To find the missing side, you have to run through the Pythagorean Theorem and find out what the missing side is.
a = 25 feet
b = 10 feet
c = ?
a² + b² = c²
25² + 10² = c²
625 + 100 = c²
725 = c²
square root
of 725 = c²
Now we make the fractional then decimal form of the square root of 725.
Since 26 is 1 unit larger than 25, we have to square the number 26 and subtract that number from 725 (725 - 676).
27 x 27 = 729 - we can't use this because its larger than 725
26 x 26 = 676
So, back to the subtraction:
725 - 676 = 49
49 becomes the numerator of the fraction after 26.
To find the denominator, you have to add 26 with the number after it, which is 27
26 + 27 = 53.
The answer to 725 squared = 26 49/53
But we aren't done yet, we have to make it into a decimal form. *opens calculator*
26 49/53 = 26.924
26.924 = C
26.924² = c²
So the missing side length of the picture above is 26.924.























Another way we could have found the fraction after 26 is doing the "mullet" strategy.
















D = Denominator of fraction after 26

Thursday, January 24, 2008

Robby's Scribe Post

Today, we did a test on adding, subtracting, and multiplying fractions.

THE QUESTIONS WERE:
1 1/5 + 3 2/3 =


5 3/4 - 3 5/6 =

7/8 x 4/5 =

2 2/3 x 4 1/2 =

I answered the questions on Microsoft Pain
t -like application:

1 1/5 + 3 2/3=


For th
ose of you that CAN'T SEE, the writing under the question says: Now make Equivalent Fractions. FOr 1/5 and 2/3, they both go into 15. So multiply numerator of 1 by 3 and the numerator of 2/3 by 5. The denominator will be set at 15.
*Circled areas are answers or part answers.

5 3/4 - 3 5/6 =

STEPS I TOOK:
I (wife) swapped 3/4 and 5/6 to get 5/4 and 3/6. 3/6 is half and 5/4 = 1 1/4.(new question being 6 1/4 - 3 3/6.
Then, I turned 3/6 into 1/2 and did simple subtraction with the wholes. With the fractions, I turned 1/2 into 2/4 to have a common
denominator.
The question now is 6 1/4 - 3 2/4. But you can't subtract 2/4 from 1/4, so you need to BORROW a whole from 6 and add it to 4. 1 Whole is 4/4 for this question. So add 4 to 1 to get 5/4. Now you can subtract it with a proper fraction as the answer.


7/8 x 4/5 =
A much faster way to do this is just multiplying and simplifying.
If any of you have caught, i turned 7/5 into a mixed then back to an improper. My mistake, too lazy to fix because i can take half a minute to write this explaining instead of taking a half hour and doing this whole thing again.
7 x 4 is 28
8 x 5 is 40
28/40 ÷ 2 = 12/20
12/20 ÷ 2 = 6/10
6/10 ÷ 2 = 3/5.

Hmmmmmmmm
the answers are different for both strategies. I guess it DOES make a difference if you swap.

2 2/3 x 4 1/2=
Enlarged to view writing.

&*(&*(&(*&(*&(*&(*&(*&(*&(*&&(*&(*&(*(*&(*&(*&(*&(*&(*

Well, thats my scribepost. Took a good 2 hours because i was using this new paint program, which turned out it stunk and wasted my time. , =P ,>_> ,<__<>_<> =o