LEARNING PERCENTS
in the Land of ...
Welcome to Mathtropolis
A Land of Mathematical Relations
Mathtropolis is a place where we will meet interesting people who have mathematical identities . A place where you will be building some of your existing skills with the help of these residents and their friends and families .
There are many math operations that are learned during our school years, and the land of Mathtropolis may help you to learn and better remember them.
Welcome to Thyme Stables , owned by Mel T. Ply . Mel keeps his horses in a big square barn that has 10 rows of horse stalls that are each 10 stalls deep. He fills the stalls beginning at the front of the barn and tries to keep them filled in such a way that he can easily count the number of his horses.
Mel has seven rows of stalls filled with one horse each in stalls one through six. How many horses does Mel have in the barn?
This is Dee Vision, the mayor of Mathtropolis. She likes to know how the people of Mathtropolis feel, and to do this she takes a lot of opinion polls . She found that 63 out of the 100 people in town this year think that she is doing a good job.
When she asked what the most important issues in Mathtropolis were, she learned that 32 people wanted better roads, 13 people wanted the park open later on weekends, 24 people wanted lower taxes, 17 people wanted better garbage collection and 14 people wanted better schools.
She takes the results of her polls to decide how to best help the town improve as she has done for the last three years she has been mayor. To find out how the people's opinions have changed over the years, she takes the results of her poll and divides them by the number of people polled each year. Doing this makes it easier for her to compare the results of any year with another.
Why do you think she performs this division ?
She says:"Many of the residents of Mathtropolis have to understand how to use fractions . If you speak with my cousin Ray Show, you might learn more. You'll probably find him at the Pythagorean Tea Room eating one of Sir Cumference's pies."
A popular meeting place in Mathtropolis is the Pythagorean Tea Room . People come from miles around to try Sir Cumference 's famous pies. Here we meet Ray Show who will tell us a little about these delicious treats.
Ray shows us that one of Sir Cumference's pies is cut into eight equal sized slices. Ray tells us that if we want to know how much of the pie we ate, we take the part and divide it by the whole. In other words, we take the number of slices eaten and divide it by the total number of slices in the pie.
If you eat two slices of pie, what part of the pie have you eaten?
Ray talks about the parts of the pie and says that we can compare them as percentages instead of fractions. To make a fraction into a percent, we have to set up a proportion where we set the fraction equal to some number divided by 100.
If we have half of the pie, what percent of the pie would that be?
To calculate that, we would set one half equal to the percentage divided by 100.
For this example, we will let x be the percentage of the pie.
½ = x ÷ 100
½ × 100 = x
x = 50%
What percent of the pie is ¾ of the pie?
Ray told us that the portion of the pie can also be described as a percentage . Percentages are useful since they are describing the fractions as parts out of 100. To calculate percentages, we take the part divided by the whole and that will equal the percent divided by 100.
We are able to represent the fractions as whole numbers when we use percentages which sometimes makes the relation of numbers easier to see.
If you were told that 32 people out of 80 made more money when investing with Moe's Money Market last year while only 26 people out of 50 made money investing with Phil's Financial Factory during the same period, Who would you invest your money with?
We hope you have had fun visiting Mathtropolis. We certainly enjoyed sharing our town with you.
We think there are many interesting things that can be done with mathematics and what we did is just a small percent of that.
We hope we can count on you to find the pluses in math.
In the words of Sir Cumference: "Have fun, see you around!"
