Narnia Math: Elementary Problem Solving 4th Grade

Posted on by Denise Gaskins

[Photo by armigeress.]

In 4th grade, math problems take a large step up on the difficulty scale. Students are more mature and can read and follow more complex stories. Multi-step word problems become the new norm, and proportional relationships (like “three times as many”) show up frequently. As the year progresses, fractions grow to be a dominant theme.

As a math teacher, one of my top goals is that my students learn to solve word problems. Arithmetic is (relatively) easy, but many children struggle in applying it to “real world” situations.

In previous posts, I introduced the problem-solving tools of word algebra and bar diagrams, either of which can help students organize the information in a word problem and translate it into a mathematical calculation. The earlier posts in this series are:

In this installment, I will continue to demonstrate the problem-solving tool of bar diagrams through a series of ten 4th grade problems based on the Singapore Primary Math series, level 4A. For your reading pleasure, I have translated the problems into the universe of a family-favorite story by C. S. Lewis, The Lion, the Witch and the Wardrobe.

UPDATE: Problems have been genericized to avoid copyright issues.

Continue reading Narnia Math: Elementary Problem Solving 4th Grade

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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Mental Math: Addition

Posted on by Denise Gaskins

[Photo by woodleywonderworks.]

The question came from a homeschool forum, though I’ve reworded it to avoid plagiarism:

My student is just starting first grade, but I’ve been looking ahead and wondering: How will we do big addition problems without using pencil and paper? I think it must have something to do with number bonds. For instance, how would you solve a problem like 27 + 35 mentally?

The purpose of number bonds is that students will be comfortable taking numbers apart and putting them back together in their heads. As they learn to work with numbers this way, students grow in understanding — some call it “number sense” — and develop a confidence about math that I often find lacking in children who simply follow the steps of an algorithm.

[“Algorithm” means a set of instructions for doing something, like a recipe. In this case, it means the standard, pencil and paper method for adding numbers: Write one number above the other, then start by adding the ones column and work towards the higher place values, carrying or “renaming” as needed.]

For the calculation you mention, I can think of three ways to take the numbers apart and put them back together. You can choose whichever method you like, or perhaps you might come up with another one yourself…

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Quilt: What Can You Do with This?

Posted on by Denise Gaskins


[Ragged Squares Quilt photos used with permission from Crazy Mom Quilts.]

I know other teachers have done math quilts, but I’ve never gotten around to trying it in any of my classes. Still, this image caught my eye and practically begged me to make it into a math lesson for my elementary math club.

I thought of at least two ways I could go with this, but I bet that if we put our brains together, we can come up with even more creative ideas. So here’s the question, ala Dan Meyer:

  • What can you do with this?

How could you use this image as a springboard to doing math? What questions would you ask? What concepts would you try to get across? What would you follow it with? Please comment!

Other photos are available…

Continue reading Quilt: What Can You Do with This?

Math Facts: 5 Minutes a Day

Posted on by Denise Gaskins

free-rice-image

Y of x reminded me about one of my old favorite websites for math fact practice with a purpose:

5-10 minutes of daily practice will cement the math facts in your student’s mind, while at the same time doing a good deed. For each correct answer, a Free Rice sponsor donates a very small amount of rice to feed hungry people worldwide through the UN World Food Program.

Even very small amounts of rice add up. Since Free Rice started in 2007, its sponsors have bought more than 63 billion grains of rice, just by paying for one right answer click at a time.

You and your students can practice other topics as well:

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Can You Read the Flu Map?

Posted on by Denise Gaskins

swine-flu-map-with-circles
[Map as of early afternoon on May 4th, found at the NY Times.]

Compare the dark circles (confirmed cases) for Mexico, New York and Nova Scotia in the top part, or Mexico and the U.S. in the lower part of the map. It’s easy to see which has more cases of the flu — but how many more? Which would you guess is the closest estimate:

Mexico : New York : Nova Scotia

  • = 7:3:2 or 20:5:3 or 16:2:1?

U.S. : Mexico

  • = 1:2 or 2:5 or 3:7?

Continue reading Can You Read the Flu Map?

Tangrams and Other Dissection Puzzles

Posted on by Denise Gaskins

tangram-cat[Photo by jimmiehomeschoolmom.]

One of the things I meant to do with my elementary math class (the one that got canceled due to low enrollment):

And then we would play around with Tangram puzzles, and perhaps make up a few of our own.

Continue reading Tangrams and Other Dissection Puzzles

Kids’ Project: More Math Calendars?

Posted on by Denise Gaskins

tulips-by-kuzeytac[Photo by Kuzeytac.]

Several people enjoyed the April calendar and asked if there would be a May version. Unfortunately, my homeschool co-op classes are out until next fall, so I don’t have enough kids to make up problems for me. But if your children would like to send in some puzzles, I will be glad to put another calendar together. If we get enough participation, we could have calendars every month for the rest of the year!

Continue reading Kids’ Project: More Math Calendars?