First let’s set up the problem:
520÷21 Step 1:
Take the whole number, 21, and multiply it by the denominator of the fraction, 5:
5 x 21 = 105
Step 2:
The result of this multiplication will now become the denominator of the answer. The answer to the problem in fraction form can now be seen:
205⋅21=20105 To display the answer to 20/5 Divided by 21 in decimal form, you can divide the numerator, 105, by the denominator, 20. The answer can be rounded to the nearest three decimal points, if needed:
20105=421=5.25 So, in decimal form, 20 divided by 5/21 = 5.25
And in its simplest fractional form, 20 divided by 5/21 is 21/4