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FRACTIONS With Scooby Doo by Mr. Meute, Foster Elementary Fourth Grade

Always Click on Scooby to Continue

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Scooby and the gang have a mystery to solve and they need your help

Scooby and the gang have a mystery to solve and they need your help! So far, all of the clues seem to involve fractions. So, before they let you use your detective’s skills, you have to show them that you’re a fractions expert!

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Do you have what it takes to join us and help solve this mystery

Do you have what it takes to join us and help solve this mystery? We’ll lead you through a review of fractions and you might even learn something new. Then we’ll ask you some questions and if you can answer them all by the end of this class period, we’ll give you a copy of our notes with all of the clues we’ve found so far. Maybe you’ll be able to figure out how the clues fit together. We’re counting on you, so let’s get started!

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What is a fraction?

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Remember, a fraction is a number that names a part of a whole or a part of a group.

Fractions are written as two numbers with a bar between them like this . . . 3 4 This fraction is read as “three fourths.”

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3 4 Three fourths of the rectangle is yellow.

The numerator tells the number of parts shaded or shown 3 4 The denominator shows the total number of parts Three fourths of the rectangle is yellow.

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What fraction of this rectangle is shaded orange?

3 8 5 8 8 3 8 5

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That’s RIGHT! 5 8 of the rectangle is orange. Let’s keep going!

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Not Quite . . . 3 8 of the rectangle is yellow, not orange. Try Again!

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Be careful . . . Remember, the numerator (top number) tells the number of parts shaded. Try Again!

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What are equivalent fractions?

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Equivalent fractions show the same, equal amount.

2/3 , 4/6 , and 6/9 are equivalent fractions. The shaded areas are the same size.

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You can find some equivalent fractions by multiplying the numerator and denominator by the same number. X 2 2 3 4 6 equals X 2

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You can find other equivalent fractions by dividing the numerator and denominator by a common factor. ÷ 3 9 3 4 equals 12 ÷ 3

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X ? 1 2 4 8 = What number have the numerator and denominator been multiplied by? 3 2 4

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Excellent! I knew you could do it. 1 X 4 = 4 and 2 X 4 = 8

Let’s move on!

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No, think again . . . What number times two equals eight? go back

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÷ ? 6 3 5 = 10 What number have the numerator and denominator been divided by? 3 2 4

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That’s right! 6 ÷ 2 = 3 and 10 ÷ 2 = 5 Let’s keep going!

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No, think again . . . Ten divided by what number equals five? go back

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How do I write a fraction in simplest form?

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To write a fraction in simplest form you need to use equivalent fractions and common factors. A fraction is in simplest form when the only common factor the numerator and denominator have is 1. Remember, a common factor is a number that is a factor of two or more numbers. Factors of 12: 1, 2, 3, 4, 6, 12 Factors of 15: 1, 3, 5, 15 So, 1 and 3 are common factors of 12 and 15.

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These fractions are in simplest form.

The only common factor of 3 and 4 is 1. 1 3 5 6 7 9 2 5 3 4

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These fractions are not in simplest form.

6 2 8 3 9 4 6 2 4 10 6 and 10 have two common factors: 1 and 2.

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Which of these fractions is not in simplest form?

9 5 8 10 10 12 3 7

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10 12 is correct! 10 and 12 have more than one common factor, since 1 and 2 are both factors of these numbers.

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No, remember a fraction is in simplest form when 1 is the only common factor of the numerator and denominator. Try again.

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Which of these fractions is in simplest form AND equivalent to 10/15 ?

15 10 2 3 6 9 3 4

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Correct again! If you divide both the numerator and the denominator by 5, you will get the equivalent fraction in simplest form of 2/3.

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Not exactly . . . Yes, 6/9 is equivalent to 10/15. However, it is not in simplest form. One more time

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No, remember you must divide the numerator and the denominator by the same number to get an equivalent fraction in simplest form. Try again

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How do I put fractions in order?

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One way to compare fractions is to use fraction bars.

The yellow area is larger than the orange area, so 3/4 is greater than 2/3.

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Another way to compare fractions is to find equivalent fractions with the same denominator.

1 2 3 8 Which is greater? or We can write 1/2 as an equivalent fraction with the denominator 8. 4/8 is equal to 1/2. Now we can compare the two fractions and see that 4/8 is greater than 3/8. That means that 1/2 is greater than 3/8 too.

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Choose the greatest fraction.

3 5 2 4 4 6 4 7

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Of Course! 4 6 is the greatest fraction because it has the largest shaded area. Now try another one.

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Nope! Try again! Remember, it’s the fraction bar with the largest shaded area.

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Can you put these fractions in order from least to greatest?

3 4 1 2 7 8 1 2 3 4 7 8 7 8 1 2 3 4

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That’s Right! 1 2 3 4 7 8 is less than is less than Because if you use 8 as the denominator and form equivalent fractions 4/8 is less than 6/8 which is less than 7/8.

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No, Try again . . . This time try forming equivalent fractions with the same denominator so they will be easier to compare.

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Like, WOW! You really are a fractions expert! There’s just one more thing left to do before you can help us with this mystery . . .

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Fractions review Hey, don’t run away now! You’re almost finished.

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Click here to end the show

Think about these questions and answer them in your Scooby Workbook. You’ll find them on the first page. TRUE FALSE 1. The numerator in a fraction shows the total number of parts. 2. Fractions that have the same denominator are equivalent fractions. 3. 2/3 is equal to 6/9. 4. It is possible to find equivalent fractions by dividing the numerator and denominator by a common factor. 5. A fraction is said to be in simplest form when the only common factor the numerator and denominator have is 1. 6. The fraction 6/14 is in simplest form. 7. 4 is a common factor of 8 and 24. 8. When comparing fractions, you must use fraction bars or models when the denominators are different. 9. 2/4 is greater than 4/12. 10. These fractions are in order from least to greatest: 1/2 , 7/12 , 5/6 Click here to end the show

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