Subtracting Fractions

Probably starting in fourth grade math, and then receiving strong emphasis in fifth grade math and sixth grade math, your child learned the operations for fractions.

That is, how to do the four arithmetic operations of addition, subtraction, multiplication and division with fractions, or with combinations of fractions, mixed numbers and whole numbers.

The next step, and this topic is addressed throughout the middle school years, is Applications of Fractions. That means understanding when to use the different operations in the context of real life fractions situations.

This page is focusing solely on the real-life application of subtracting fractions.

If your upper elementary or middle school child really doesn't know the fraction operation of subtraction confidently, and doesn't know how or when to get a common denominator, you really need to work with him or her first on learning these basic steps (Scroll down to the bottom of this page for my TOP recommeded fractions practice materials.)

OK, so assuming your child knows how to do operations with fractions pretty well, let's look at the applications. The real trick for this is recognizing the English words that point to the given operation. Another way to look at it is, recognizing the typical situations that relate to a given operation.

Here's a simple problem involving subtracting fractions to see if your child knows how to compute:

• Augustus had 4 1/2 sugar doughnuts. He ate 2 1/3 of his doughnuts. How many doughnuts did he have left?

4 1/2 – 2 1/3

4 3/6 - 2 2/6 (get a common denominator)

2 1/6 (subtract the whole numbers and the numerators)

You don’t find the word “subtract” or “minus” or even “take away,” the elementary school synonym for subtract.

What you do find is a situation with the concept of taking away, reducing, going down, decreasing, etc., which in this case is eating the doughnuts.

Anytime in a word problem where we have a situation involving decreasing, taking away, using up, or the like, it will be a subtraction situation.

Here are some more examples:

• Prospector Zeke found 10 3/4 ounces of pure gold in the Klondike River, however, he dropped 3/8 of an ounce on the way back into town. How much did he have left?
• Minnie weighed 174 1/4 pounds. On the first week of her diet, she lost 5 1/2 pounds. How much does she weigh now?
• Able Baker Charlie had 7 1/2 pounds of flour, he used up 1 5/8 pounds baking pretzels. How many pound of flour does Able Baker Charlie have left?

Do you see how in all these examples there is an underlying idea of reducing, taking away, going down, losing, spending, using up?

There are so many ways in English that this idea can be expressed, it’s really best for the student to look out for the idea, rather than a specific word.
Now, let me speak as a concerned teacher, to you, a concerned parent...

If your child can't, unassisted, accurately compute the simple problems involving subtracting fractions that I've given above, it's time for you to take action!

Your child needs help understanding the basics of subtracting fractions.

This is not necessarily a sign of a learning difficulty, but more likely that your child's teacher never spent enough time teaching and practicing subtracting fractions in the classroom.

It takes weeks of incremental skills development and practice to gain facility with subtracting fractions!!! Did your child's teacher give him that? (You may be interested to read about some of the problems in today's American Math education to learn more about this phenomenon.)

To help your child bridge his or her knowledge gap, here are my TOP RECOMMENDED practice books for you to use with your child.

I only recommend products that I have used successfully in my classrooms, and in my own home with my children. (Cost matters too. We can buy good math practice books and tools without breaking the bank!)

For 4th Grade Math Practice:

• Kumon 4th grade math practice books are well presented and organized. At $6.95, its a great value compared to other math workbooks!
• For homeschoolers and those interested in more intense math practice at home: I would recommend this Saxon Publishing 4th grade math practice book. I have not only successfully used the Saxon materials in the classroom, but I have contributed and edited a text book for them. Their math materials are superior!
• And, I'm positive your children will love these as much as mine do. These fun fractions tiles will help visually demonstrate the operation of adding fractions. Use them as you're working out fractions problems together with your child.

• Kumon 5th grade math practice books are tops for zeroing in on one skill and working on incremental fractions skill development. At only $6.95 (and eligible for FREE Shipping) from amazon.com) they are a real bargain!
• For Homeschoolers and parents who want more intense at-home math practice, you should consider the practice books and products in Saxon Math's excellent series of math instruction books.

• Kumon 6th grade math practice booksare tops for zeroing in on one skill and working on incremental fractions skill development. At only $6.95 (and eligible for FREE Shipping from amazon.com) they are a real bargain!
• For Homeschoolers and parents who want more intense at-home math practice, you should consider the practice books and products in Saxon Math's excellent series of math instruction books.

Take me back from Subtracting Fractions to the Sensible Math Education home page

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Show me the application of Multiplying Fractions

Show me the application of Dividing Fractions

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