Start you know you want to have 3/4= something over 28

So let's write this out as an equation: 3/4=x/28

Now let us multiply both sides by 28 so that we get: 28(3/4)

Now the 4 is cancelled out by the 28, turning the 28 into a seven because 4 goes into 28 7 times.

This leaves us with 7*3 (* means multiplied by) = x

Therefore 21 is the numerator of the new fraction.

So let's write this out as an equation: 3/4=x/28

Now let us multiply both sides by 28 so that we get: 28(3/4)

Now the 4 is cancelled out by the 28, turning the 28 into a seven because 4 goes into 28 7 times.

This leaves us with 7*3 (* means multiplied by) = x

Therefore 21 is the numerator of the new fraction.