1. Fraction Follies by D. Fisher
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by D. Fisher

2. 1. a. What fraction is shaded?
1/5
This problem comes from the Mathematics Case Methods Project by WestED 2003.
b. Why is one fifth wrong?

3. 1. a. What fraction is shaded?2 3 4 5 6 7 8
c. Why is one fourth right?
1/4
2/8 = 1/4

4. 2. a. Reduce the fraction 8/12 to lowest terms.
1 4/12
b. Why is one and four twelfths wrong?

5. 2. a. Reduce the fraction 8/12 to lowest terms.
4/6
c. Why is four sixths wrong?

6. 2. a. Reduce the fraction 8/12 to lowest terms.
2/3
d. Why is two thirds correct?
1/3
1/3 8 12
8 ÷ 4
12 ÷ 4 = = 2 3
1/3

7. 3. a. Multiply 2/3 by 4/7.
12/14
b. Why is twelve fourteenths wrong?

8. 3. a. Multiply 2/3 times 4/7.
8/21
c. Why is eight twenty-firsts right?

9. 3. a. Multiply 2/3 times 4/7.
8/21
c. Why is eight twenty-firsts right?

10. 3. a. Multiply 2/3 times 4/7.
8/21
c. Why is eight twenty-firsts right? 4 7 2 3 x
2 x 4
3 x 7 = = 8 21

11. 4. a. Divide 2/7 by 3/5 .
6/35
b. Why is six thirty-fifths wrong?

12. 10/21 4. a. Divide 2/7 by 3/5 . c. Why is ten twenty-firsts right? 3 5÷ 2 7 = 5 3 x
2 x 5
7 x 3 = = 10 21

13. 5. a. Change 4 2/5 to an improper fraction.
42/5
b. Why is forty-two fifths incorrect?

14. 5. a. Make 4 2/5 an improper fraction.
13/5
c. Why is thirteen fifths wrong?

15. 5. a. Rewrite 4 2/5 as an improper fraction.
22/5
d. Why is twenty-two fifths right? 2 5 4
4 x 5 + 2 5 = = 22 5

16. 6. a. Add 1/2 plus 2/5 .
3/7
b. Why is three sevenths not right?

17. 9/10 6. a. What is 1/2 plus 2/5 ? c. Why is nine tenths correct? 1 2 5+
2 x 2
5 x 2 =
1 x 5
2 x 5 = 5 10 4
9/10 9 10
c. Why is nine tenths correct?

18. 7. a. Multiply 1 1/2 by 2 3/5 .
2 3/10
b. Why is two and three tenths incorrect?

19. 7. a. Multiply 1 1/2 times 2 3/5 .
3 9/10
c. Why is three and nine tenths correct? 3 5 1 2 x 13 5 x 3 2 =
3 x 13
2 x 5 = = 39 10 9 10 = 3

20. Don’t have any
Fraction Follies!