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7th Grade Lesson for Tuesday November 22nd In this lesson, you will continue to work on proportions and percents. In particular, you'll be calculating the percent of a number First, it's important to understand how calculating a percent of a number is just like calculating a proportion. For example, 40% of 200 We know that 40% is the same as 40 out of 100. We can write that as a fraction: 40% = 100 40 Since... We can then compare that to an equivalent proportion. This is like saying... If 40 out of 100 students like ham sandwiches, how many in a school of 1000 will like them? To solve this, we'd write a proportion: x = 100 40 40 x 1000 100 40% = = 1000 100 = 400 x 40 Instead of saying 40 out of 100, we could just say 40%. If 40% of the students like ham sandwiches, how many students out of 1000 will like them? This would be the same proportion: x = 100 40 40 x 1000 100 = 1000 = 400 x Let's make sure you are getting this: If 60% of the students like Turkey sandwiches, how many out of 800 will like them? Fill in the missing spaces and use your calculator to find the final answer. = x= This is the last slide for Part I. If you did this correctly, you will receive a 100% on this portion. If there is a mistake, it will require you to retake this portion. Please take your time and read each slide carefully, so that you'll be ready to go on to the next section. |