REDUCING FRACTIONS

Question

HOW DO i REDUCE 18/48

Answer 1

To reduce fractions, it helps to know your multiplication tables really well.

1. First take the smaller of the numbers, 18.

2. List the ways to get 18 by multiplying. You can guess, or go systematically...

    1 x 18, 2 x 9, and 3 x 6. (4 and 5 don't go into 18. Stop once you get the same product in reverse, like 6x3)

3. For each new number you get  (1x18 doesn't count) do the same thing-- list the ways you can get those numbers by multiplying.

   2

   9 =3x3

   3

   6 =2x3

   That's all the factors of 18!

5. Next check to see which of those factors from 18, can be divided out of 48 with no remainder.

   9: you can't take 9 out of 48, but you can take 3 out.

      48 / 3 = 16

      That means you can take 16 / 48 and divide 3 out from each to get: 6 / 16.

      Now, see if 6/16 can be reduced using the factors you found.

   6: you can't take 6 out of 16, but you can take 2 out to get: (6/2) / (16/2) which is 3/8.

Once you know about prime numbers, reducing fractions gets even easier.

 

Answer 2

If you're having difficulties with reducing fractions, do the simplest things you know. In this problem, you may not know the greatest common factor. Since each number is even, pull out a 2 from both 18 and 48.

18/48 = (2)(9)/(2)(24). The 2's you pulled out cancel so you have 18/48 = 9/24. Now, you know that 9 factors into 3 * 3 and 24 = 8 * 3. Again, pull out the 3's so that they cancel and you're left with 3/8.

Answer 3

actually it's put in lowest terms. You find the GCF (greatest common factor) of the numerator and denominator, the highest number that divides without a remainder into each. Here it is 6. 18/6 is 3, and 48/6 is 8, so the answer is 3/8.

Answer 4

There is an even better way to reduce fractions, assuming you may not know the common factors of the numerator and denominator. It is called Euclid's algorithm and is best suited of big numbers.

Example: GCF(18,48)

              =GCF(12,18) as 48=2*18+12

              =GCF(6,12) as 18=1*12+6

              =GCF(0,6) as 12=2*6+0

              =6

So we divide both the numerator and denominator by 6 to get 3/8