Arithmetic Grade Five

Lesson Eighteen: Fraction Review


Equivalent Fractions
Here's the list of fractions which are equivalent to three-fourths again.

You should go through this list and see if you can figure out what the numerator and denominator of 3/4 must be multiplied by to get each answer. Here's a little help, if you need it:
ORIGINAL FRACTION MULTIPLY TOP AND BOTTOM BY RESULTING EQUIVALENT FRACTION
3/4 3 9/12
3/4 5 15/20
3/4 7 21/28
3/4 10 30/40
3/4 100 300/400
3/4 40 120/160
3/4 2 6/8
Remember the process we use to figure out a problem like this:


      8       ?
     ---  =  ----
      9       27

  1. divide second denominator by first denominator (27 / 9 = 3)
  2. multiply top numerator by answer to first step (8 x 3 = 24)
Apply these steps to each of the following example:

ORIGINAL FRACTION MULTIPLY TOP AND BOTTOM BY RESULTING EQUIVALENT FRACTION
7/8 3 21/24
5/6 5 25/30
1/3 7 7/21
5/7 10 50/70
Now you can try out this little JavaScript calculator:





To find the value of n2, multiply d2 and n1. Divide this product by d1. In other words, n2=d2*n1/d1.
Replace n1, d1, and d2 with numbers. Press the button and n2 will automatically display a correct numerator. For some sets of numbers n2 will become a decimal value.

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