2010 Mathematics Game

Posted on by Denise Gaskins


[Photo by pfala.]

Did you know that playing games is one of the Top 10 Ways To Improve Your Brain Fitness? So slip into your workout clothes and pump up those mental muscles with the 2010 Mathematics Game!

Here are the rules:

Use the digits in the year 2010 to write mathematical expressions for the counting numbers 1 through 100.

  • All four digits must be used in each expression. You may not use any other numbers except 2, 0, 1, and 0.
  • You may use the arithmetic operations +, -, x, ÷, sqrt (square root), ^ (raise to a power), and ! (factorial). You may also use parentheses, brackets, or other grouping symbols.
  • You may use a decimal point to create numbers such as .1, .02, etc.
  • Multi-digit numbers such as 20 or 102 may be used, but preference is given to solutions that avoid them.

Bonus Rule
You may use the overhead-bar (vinculum), dots, or brackets to mark a repeating decimal.

[Note to teachers: This rule is not part of the Math Forum guidelines. It makes a significant difference in the number of possible solutions, however, and it should not be too difficult for high school students or advanced middle schoolers.]

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Algebra: A Problem in Translation

Posted on by Denise Gaskins

[Photo by *Irish.]

In my post Elementary Problem Solving: The Tools, I introduced word algebra as a way to help students think their way through a story problem. In the next two posts, I showed how the tool worked with simple word problems.

Now, before I move on to focus exclusively on bar diagrams, I would like to show how word algebra can help a student solve a typical first-year algebra puzzle.

A homeschooling friend who avoided algebra in high school, trying to help her son cope with a subject she never understood, posted: “Help! Our answer is different from the book’s.” Here is the homework problem:

Josh earned $72 less than his sister who earned $93 more than her mom. If they earned a total of $504, how much did Josh earn?

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Elementary Problem Solving: Review

Posted on by Denise Gaskins

[Bill Watterson identifies the trouble with math problems, through the eyes of Calvin and Hobbes.]

It’s time to revive and (hopefully!) finish my long-neglected series on solving word problems in elementary mathematics. I’ve been having fun making up the problems, so now I just have to write the posts. Coming up soon:

Since it has been more than two years since the last entry, however, I wanted to take a few minutes to recap our progress so far and to refer new readers back to the original posts:

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Do Your Students Understand Division?

Posted on by Denise Gaskins

Cheerios by sixes
[I couldn’t find a good picture illustrating “division.” Niner came to my rescue and took this photo of her breakfast.]

I found an interesting question at Mathematics Education Research Blog. In the spirit of Liping Ma’s Knowing and Teaching Elementary Mathematics, Finnish researchers gave this problem to high school students and pre-service teachers:

We know that:
498 \div 6 = 83
How could you use this relationship (without using long-division) to discover the answer to:
491\div6=?
[No calculators allowed!]

The Finnish researchers concluded that “division seems not to be fully understood.” No surprise there!

Check out the pdf report for detailed analysis.

Continue reading Do Your Students Understand Division?

How to Solve Math Problems

Posted on by Denise Gaskins

[Photo by Aaron Escobar. This post is a revision and update of How to Solve Math Problems from October, 2007.]

HowToSolveIt2

What can you do when you are stumped by a math problem? Not just any old homework exercise, but one of those tricky word problems that can so easily confuse anyone?

The difference between an “exercise” and a “problem” will vary from one person to another, even within a single class. Even so, this easy to remember, 4-step approach can help students at any grade level. In my math classes, I give each child a copy to keep handy:

[Note: Page 1 is the best for quick reference, especially with elementary to middle school children. Page 2 lists the steps in more detail, for the teacher or for older students.]

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Happy Square Root Day!

Posted on by Denise Gaskins

square-roots-by-arsheffield
[Photo by arsheffield.]

Check it out:

And coming soon: Pi Day.

Edited to add: Jonathan‘s class enjoyed extending the concept to include other products. Using the m/d/yy format (not the 4-digit year), how many times in your life has it been true that month \times day = year ?

MathNotations Contest for Middle-High School

Posted on by Denise Gaskins

math-team-edit
[Photo by ccarlstead.]

Can you can put together a team of 2-6 middle or high school students for an afternoon of mathematical play? If so, then Dave at MathNotations is running a math competition you just have to check out.

Teachers register by email on or before Thursday, January 29, and will receive the six thought-provoking contest problems and official answer form by return email. Hold the contest at your convenience on Tuesday, February 3, allowing your team up to 90 minutes to complete and electronically submit their answers.

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Free Online Math for Middle School and Up

Posted on by Denise Gaskins

alcumus

The Art of Problem Solving people recently announced their new Alcumus program, which provides online lessons on assorted math topics, including probability and combinatorics, which most math textbooks do not cover well, if at all.

Update October 2011:

Alcumus currently complements our Introduction to Algebra, Introduction to Counting & Probability, Introduction to Number Theory, and Prealgebra textbooks, as well as our Algebra 1, Algebra 2, Introduction to Counting & Probability, Introduction to Number Theory, and Prealgebra 1 online courses. We expect to continue to expand topics in Alcumus.

— AoPS Alcumus information page

I am signing up all my MathCounts students. If you’re a homeschooler, we would love to have you join us!

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2009 Mathematics Game

Posted on by Denise Gaskins

new-year
[Photo by Amanda M Hatfield.]

Have you made a resolution to exercise your mental muscles this year? Then please join us for the 2009 Mathematics Game. Here are the rules:

Use the digits in the year 2009 and the operations +, -, x, ÷, sqrt (square root), ^ (raise to a power), and ! (factorial) — along with parentheses, brackets, or other grouping symbols — to write expressions for the counting numbers 1 through 100.

  • All four digits must be used in each expression.
  • Only the digits 2, 0, 0, 9 may be used.
  • The decimal point may be used, as in .9, .02, etc.
  • Multi-digit numbers such as 29 or 902 may be used, but preference is given to solutions that avoid them.

By definition: 0! = 1 .
[See Dr. Math’s Why does 0 factorial equal 1?]

For this game we will accept: {0}^{0} = 1 .
[See the Dr. Math FAQ 0 to the 0 power.]

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MathCounts — Ready or Not, Here It Comes

Posted on by Denise Gaskins

[Feature photo above “You’re a mean one, Mr. Grinch” from CheezBurger.com.]

Okay, kids, I know you’re on break, but Mr. Grinch would tell you that’s no excuse to laze around playing games and eating cookies. There is only a month until our school MathCounts competition, which doesn’t give you much time to prepare. I’ve collected several resources to build up your mental muscle-power before the test…

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