Extra Credit Problems:
You have one week from the day the problem is posted to turn in your solution for extra credit. Your paper should include your name, your answer, and all your work showing how you arrived at your solution.
Week of May 24 to May 28:
Solve this krypto problem: 14, 2, 17, 23, 6 to get 25.
Week of May 3 to May 7:
Find a newspaper, magazine or journal article on a topic that interests you. Pick a statistic from the article (sports, business, fashion, economics, investing, weather, science, census etc) and explain why it is a good measure of something, "good" meaning accurate and representative, not misleading, etc. Also, explain how the statistic is derived, in other words, what is the math calculation being done?
Week of April 26 to April 30:
This week's problem is a
trip to the future. Your future! Imagine that it is the year 2020. You
have recently finished college and you are working successfully at your
first full-time adult job. This is something that you have wanted to
do for a long time. Describe at least one aspect of your job that
requires mathematical, quantitative or logical thinking and analysis by
you on a regular basis. (If you are not sure, you might have to talk to
someone who actually does this job now.)
Week of April 19 to April 23:
If you wish to plant some
trees so that each tree is equidistant from every other tree, what is
the largest number of trees that you can plant? Explain your
reasoning. (There are two different answers for this problem, depending on your assumptions, which you should explain.)
Week of April 12 to April 16:
What happens to the circumference of the earth if you add one inch to the diameter? What happens to the circumference of a watermelon if you add one inch to the diameter? Compare the two situations and explain your results.
Week of April 5 to April 9:
Welcome back.
2 2 2 2
The solutions of the equation a + b + c + d = (a)(b)(c)(d) may be written in the form (a, b, c, d). Find all possible values for a such that (a, 2, 2, 2) will be a solution.
(To clarify, this says "a-squared plus b-squared plus c-squared plus d-squared equals a times b times c times d)
Week of March 15 to March 18:
Spring break is almost here! Bring back a memento of your spring break that costs $2.00 or less for one point. Two points if the item has something to do with math! OR, predict the winner of the NCAA basketball tournament by Thursday of this week (no late submissions for this problem.)
Week of March 8 to March 12:
Imagine you are in a math class. At Fieldston Middle School. Your class has taken a test on which there were 20 questions. The awesome teacher comes to class the next day and says this: "Well, you all did really well, except for question number 6, which only one person answered correctly. Because of that, I have decided to score the test differently. I will either count that question as extra credit OR give everyone one free point." Which would you choose? Explain mathematically.
Week of March 1 to March 5:
A 1-quart bottle full of liquid is 10% oil, and a 3-quart bottle full of liquid is 30% oil. If the two bottles are combined, what is the percentage of oil in the mixture?
Week of February 22 to February 26:
Four 8th
graders want to cross the bridge from the high school into the middle
school. They are all starting in the high school, and they have only 17
minutes to get across. It is after gym and they have only one late
pass. A maximum of two students can cross the bridge at one time.
Any party that crosses the bridge, either one or two at a time, must have the
late pass with them. The late pass must be carried back and forth, it
cannot be thrown, for example. Each student walks at a different speed,
and if two cross together, they must walk at the slower students speed.
Collette needs
1 minute to cross.
Kat needs 2
minutes to cross.
Carter needs 5
minutes to cross.
Ian needs 10 minutes to cross.
For example if Collette and Ian walk across first, 10 minutes will have elapsed
when they get across. If Ian returns to the high school with the
late pass, a total of 20 minutes will have passed, and they will have failed
the task.
Can they all get across in the time frame?
Week of February 15 to February 19:
This week we do not have a regular puzzle or problem. Instead, read the following article from the NY Times website. If you have any thoughts to share about this, please bring them in (preferably typed).
http://opinionator.blogs.nytimes.com/2010/02/14/the-enemy-of-my-enemy/?hp
Week of February 8 to 12:
Six students stood under an umbrella. Two left and then three more came. Finally six more students came. No students got wet. How can this be?
Week of February 1 to February 5:
Anita, Cheri, Miguel, and Jake went bowling one night. For fun, they
decided to pit the girls against the boys, with the highest total score
for each team winning. Anita scored 18 less than Miguel. Cheri's score was 16 less than twice Anita's. Cheri outscored Jake by 21. If the total scored by all four kids was 529, what was the final score of the match?
Week of January 25 to January 29:
Determine the largest prime divisor of 87! + 88!.
(5! means "five factorial", which is 5 x 4 x 3 x 2 x 1)
Week of January 19 to January 22:
If it were two hours later, it would be half as long until midnight
as it would be if it were an hour later. What time is it now?
Week of January 11 to January 15:
Find two numbers within the number below, one of which is double the other, and which when added together make 10743.
57162383581
Week of January 4 to January 8:
Welcome back from vacation, mathstars!
If 73 hens lay 73 dozen eggs in 73 days and if 37 hens eat 37 kilograms of wheat in 37 days, approximately how much wheat is needed to feed enough hens to produce 1 dozen eggs?
Week of December 14 to December 18:
What
is the next letter in the sequence? Why?
O, T, F, S, N, E, __
Week of December 7 to December 11:
A Mensa puzzle: What number should replace the question mark? And why?
6 8 4 8 7 9 6 ?
Week of November 30 to December 4:
What is Grandpa's age? "My grandson is about as many days as my son is weeks,
and my grandson is as many months as I am in years. My grandson, my son
and I together are 140 years. Can you tell me my age in years?"
Week of November 23 to 24, Thanksgiving:
The Thanksgiving turkey is out for a daily run. It runs at a speed of 1 mile per hour for the first mile, 2 mi/hr for the second mile, 3 mi/hr for the third mile, 4 mi/hr for the fourth mile, 5 mi/hr for the fifth mile and 6 mi/hr for the sixth mile. What is the turkey's average speed for the entire six miles?
Week of November 16 to 20:
Four friends went fishing and brought home a total of eleven fish. If each person caught at least one fish, which one of the following must be true?
a) Somebody caught exactly two fish.
b) Somebody caught exactly three fish.
c) Somebody caught fewer than three fish.
d) Somebody caught more than three fish.
e) Two people each caught more than one fish.
Week of November 9 to 13:
Betty has 20 coins consisting of nickels and dimes. If her nickels were dimes and her dimes were nickels, her coins would be worth 70 cents more. How much are her coins worth?
Week of November 2 to 6:
A rectangular solid has a top face with surface area of 28 square feet, a front face with surface area of 20 square feet, and a side face with surface area of 70 square feet. What is the volume of this solid?
Week of October 26 to October 31:
Five members of a basketball team are weighed, and an average weight is calculated after each player is weighed. If the average weight increases by 2 pounds after each player is weighed, how much heavier is the last player than the first player?
Week of October 19 to 23:
If the reciprocal of x + 1 is x - 1, what does x equal?
Week of October 12 to October 16:
A student buys a Fieldston Eagle homecoming t-shirt for for $7, sells it for $8. buys it back for $9 and then sells it again for $10. How much profit did she make?
Week of October 5 to October 9:
Jeeves the valet was promised a salary of $8000 and a car for a year of service. When Jeeves left the job after 7 months of service, he received the car and $1600 as his prorated salary. What was the dollar value of the car?
Week of September 29 to October 2:
To conduct an experiment, a scientist needed exactly 2L of a solution. She searched her storeroom, and she could find only 5-liter containers and 8-liter containers. How could the scientist measure exactly 2L of the solution?
Week of September 21-25:
Points X(-1,1), Y(3,5), and Z(17,1) are coordinates of three vertices of a parallelogram. What are the possible coordinates of W, the fourth vertex?
Week of September 14-18:
A "section" of land is one square mile. There are 160 acres in one quarter-section of land. If one acre of land produces 42 bushels of soybeans which can be used to make 2,500 gallons of soymilk, how many gallons of soymilk can be produced from one section of land that is fully planted with soybeans?
Note: most of these problems come from the NCTM magazine "Mathematics Teacher" or Mathcounts.com
There are responses to this message:
|
