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