Daily Scribe

Daily Scribe for 3/30/10

In class we focused on percents. We would find what number a certain number was a percent of.

For example, we did the problem 216 is 72% of what number?

For this problem we asked ourselves two main questions.

1. What am I looking for?

2.What information do I already have?

We used a chart to set up a porportion, with the part over the whole. The chart was like an upside-down bar graph that showed 72% was the part of 100%, and equal to it was 216 as the part and N (the variable) as the whole.

For a word problem, we did A tile floor has 90 blue tiles, which is 15% of all the tiles in the floor. How many tiles are in the floor in all? We set up the proportion as 15 over 100 because 15% is 15/100 as a fraction and 90 over X because we knew that 90 was the part, and we were trying to find the whole.

To solve these proportions, we did cross-multipication, and then simplified to get the answer.

Another thing involving percents that we practiced was to find a percent of a specific number.For example, we did the problem 47% of 2,400. To set up the proportion, we did 47 over 100 because 47% is 47/100 in fraction form, equal to x/2,400 because we know the whole is 2,400 and the part is what we're trying to find. We did cross-multipication and got 1,128 as the final answer

Percents

Pre-Algrebra 6 6b Bt

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Fractions, Percents & Proportions

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Comparing & Scaling Problem 4.3

Comparing & Scaling Problem 4 3 Bt

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Daily Scribe

For the last couple of days, we have been doing Problem 4.1 and 4.2 in our Comparing and Scaling book. They are both about proportions.

Problem 4.1 shows us four ways to write a proportion to solve a problem.

A. This gets us to figure out what they did, how it works, and if it is correct.
B. We get to try some proportions and we have to explain to discover if we understand.
C. They give us proportions to solve and figure out if our theories from B are right.
D. We use proportions to solve sides of similar shapes.

Problem 4.2 is about everyday use of proportions.

A. How many miles burns how many calories?
B. How many miles in how many hours?
D. How many teaspoons for each dog?
E. How long is one side of a similar figure?

By now, we all have a pretty good understanding of proportions and know how to set it up and how to solve it.

Comparing & Scaling Problem 4.1 Intro

Comparing & Scaling Problem 4 1 Intro Bt

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Today in class we talked about unit rates. A unit rate is a comparison between two numbers.
For example if you could have 120 minutes of fun for $23 or 60 minutes for $11 which one would you pick? You would pick the 60 minutes for $11 because half of 120 is 60 so half of $23 is $11.50. In that case you would rather spend $11 thanhave to spend $11.50.
Another example is driving 21 miles in 30 minutes or 80 miles in 100 minutes. The answer is 21 miles in 30 minutes. If you look at it in fractions 21/30 simplifies to 7/10 and 80 miles in 100 minutes simplifies to 8/10 so the first one is the shorter drive.

In class, on February 26, we worked on problem 3.4. In the problem, you had to find unit rates. For example, you had to find out the cost per orange and how many oranges you could buy with one dollar. You also had to explain what the unit rates meant. In the problem, you had to decide which grocery store had a better buy, CannedStuff or CornerMarket.On Friday, February 26, we worked on problem 3.4.

Comparing & Scaling Problem 3.4

Comparing & Scaling Problem3 4 Summary Bt

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