## Tuesday, October 20, 2009

### Althea's BOB, BOB2, ratio, October 20/09

Today everyone has to make a BOB about ratio for us to study for Math test tomorrow.

I am going to give an example for 3 part-to-part ratio, 2 part-to-total ratio, and 2 three part ratios. Before i give you an example first I am going to define what part to part ratio is, part to whole, and three part ratios.

RATIOS

- part to part ratio- compare different parts of group to each other.

- part to whole ratio- compares one part of a group to the whole group.

- three part ratio- compares three quantities measured in the same units.
- written as a:b:c or a to b to c.

Here are the examples for each ratios:

part-to-part ratio

- blues to greens
2 : 7
- yellows to reds
6 : 10
- greens to reds
7 : 10

part-to-whole ratio

- reds to whole
10 : 25
- blues to whole
2 : 25

three part ratio

- yellow to green to red
6 : 7 : 10
- blues to yellows to green
2 : 6 : 7

I am going to pick one ratio that I have done and show it in ratio notation, fraction, decimal, and percent. The ratio I chose is reds to whole.
I have to chose one ratio that i have been written and show how to create an equivalent fraction. The ratio i chose is yellows to reds.

Now I am going to make and question and try answering it by commenting.

2. give an equivalent fraction for blues to reds.

3. can you simplify blues to whole? why or why not?

NOTE: STUDY FOR THE TEST TOMORROW AND DON'T FORGET TO BRING CALCULATOR

BOB 2

What were the mistakes you made on your test. Show examples of answers that were wrong. What was your mistake.How will you remember what to do in future tests.

- My first mistake was not putting the ratio in lowest term.

example:
A normal deck of cards has 52 card in for suits (clubs, diamonds, hearts, and spades) of 13 cards each. Two of the suits are black and two of the suits are red. The ratio of red cards to whole deck is:

-what I did wrong is that I didn't put 2:4 into lowest terms.

- My second mistake was not showing how I got the answers.

example:
In a student election Carol gets 60% of the votes. If there were 485 votes casts, how many votes did Carol get?

-what I did wrong here is that I didn't show how I got the answer. I just put how many votes she got.

How will you remember what to do in future tests?

- I will always remember to put the ratio into lowest term if the number is still even number.

- Always show how to get the answers.

Rewrite 2 questions that gave you difficulty with different numbers.

- Use the data below to determine which teams have equivalent scored by to score against ratios.
- A picture frame has a width to length ratio of 5:7. If the width of the photo is 9 cm, the length of the photo is:

a.) 11 cm b.) 12.6 cm c.) 14 cm d.) 16 cm

1. 1.
a.)>>8<< because i looked at the denominator and it looks like it's been multiplied by 4 to get 100,so what i did is i also multiplied it by 4 to get 10..i multiplied it by 4 because whatever you did to the other side you have to do it to the other
b.)>>10<< because i looked at the numerator and it's been multiplied by 2 so what i did is i divide the denominator by two because for me to get 14 to 7 is i have to divide it. 20/2 equals to 10

2.blues to reds (2:10)
equivalent fraction >> blues to reds (4:10)

3.i don't think you can because when i divided 25 by 2 it didn't equals to a whole number..

2. Awesome Scribe Post Althea!

1a) Four. It's because I look at the denominator and I knew that if you times 25 by four you get 100. Like Mr.Harbeck said what you do to the top you have to do the same thing at the bottom.

1b) It's 10. Because I know that 7 plus 7 is 14. And I can get to 7 by diving 14 by 2. So I divided 20 by 2 is 10!

2. Blues To Red is 2:10. So if i times it by two, I would get 4:20

3. You can't simplify the blues to the whole is because it's an odd number. If you try diving Blues To Whole it wouldn't be a whole at all.

3. 2.
blues to reds (2:10)
equivalent fraction >> blues to reds (4:20)

4. 1.a.8. I got 8:100 by multiplying both 2 and 25 by 4.
b.10. I got 7:10 by dividing 14 and 20 by 2.
2.blues to reds.
2 : 10
4 : 20
3.You cant simplify blues to whole because you there aren't any numbers you can divide 2 and 25 by to get a whole number.

5. a)
baseball team A- 10/8= 1.25
Hockey team A- 6/9= 0.666666666

-baseball and basketball have equivalent scored by to scored Against.

b.)
width to lenght
9 : ?
- -
5 : 7
(what ever you do to the top have to do at the bottom)
9/5 = 1.8
I am going to do the opposite of division to get the answer for the legnth of the photo.

SO THE ANSWER IS 12.6 cm (LENGTH)