How to Divide Fractions in Math

Google+ Pinterest LinkedIn Tumblr +

Step 1

The key thing to remember is the phrase “Reverse-reverse”. Think of the Cha-cha Slide, if it helps. “Reverse-reverse” is the rule for dividing fractions, which you will soon understand more deeply.

Step 2

Let’s use the problem 1/2 / 1/8 (one half divided by one eighth). Wait! Unlike in multiplication, you can’t do this straight across. A few adjustments, so to say, must be made, but later on, you will be able to  So how do you do it? By reversing the operation and the numerator and denominator of the second fraction. Division becomes multiplication. The denominator, 8, is now the numerator, and the numerator, 1, is now the denominator, for a fraction of 8/1 (eight over one). If you would like, you can also simply think of it as “opposite reciprocal”. Look below to see the example, and watch as the operation switches from division to multiplication and 1/8 (one eighth) becomes 8/1, or eight.

1                 1                1            8

–         /        –       =        –      *     –

2                 8                2            1

Step 3

And now that you have the problem set up correctly, you can multiply straight across! 1 x 8 = 8, and 2 x 1 = 2, so you get 8/2 or 4. Congratulations! You are now able to divide fractions! Soon, you can move past this building block onto more complicated math; fun!

1            8            8            4

–      *      –      =     –      =    –      =      4

2            1            2            1

Tips and Warnings

  • Don’t rule out the power of making kinetic connections; aka getting up and moving! If you’re a teacher, especially, use this in a lesson plan: get up and start dancing to the Cha-cha Slide! Pay special attention to the “reverse reverse” part; the “reverse reverse” in the song is similar to the “reverse reverse” when you switch the operation (division to multiplication) and flip the second fraction (use its reciprocal).

About Author

Leave A Reply