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“Fraction Sandwich” Practice Problems: Dividing a Fraction by a Fraction (without choking!)

November 25, 2008 · Leave a Comment

Last week I sent out a blog describing my FRACTION SANDWICH approach to dividing a fraction by a fraction. The title of the blog was: Dividing Fractions:  From Annoying to FUN!

In today’s post I offer ten solid problems that help students practice the FRACTION SANDWICH, with answers just below.

Note:  if your students struggle with these problems, it’s very possible that some of them could brush up on the rules of divisibility. For a quick review of those rules, go to:

http://mathforum.org/dr.math/faq/faq.divisibility.html

 

Try these:

a)  (2/9) / (8/12)

b)  (12/16) / (15/40)

c)  (36/21) / 63/35)

d)  (44/24) / (77/48)

e)  (15/49) / (21/56)

f)  (39/52) / (24/56)

g)  (27/45) / (33/65)

h)  (12/18) / (28/45)

i)  (17/51) / (99/121)

j)  (28/18) / (42/54)

 

Answers: 

 

a)  (2/9) / (8/12)  =  1/3

b)  (12/16) / (15/40)  = 2 

c)  (36/21) / 63/35)  =  20/21

d)  (44/24) / (77/48)  =  1 and 1/7

e)  (15/49) / (21/56)  =  40/49

f)  (39/52) / (24/56)  =  1 and 3/4 

g)  (27/45) / (33/65)  =  1 and 2/11

h)  (12/18) / (28/45)  =  1 and 1/14

i)  (17/51) / (99/121)  =  1/27  

j)  (28/18) / (42/54)  =   2

Categories: Divisibility · Division · Division Tricks · Fractions · Making Math Fun · Math Tricks · Mental Math · Uncategorized
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