Mr. R.’s World of Math

The parts of those fractions,
Their names are too tough,
Numerator,
Denominator,
Those words are too rough!
But maybe a trick,
Will help me realize,
Those words are quite easy,
A pleasant surprise!
The first letters I see,
In the word NUmerator,
Are N and U,
And now I feel greater,
Cause N and U,
Start Never Under,
And numerator’s on top,
It saves me from blunder!
And D is for down,
Like Denominator starts,
And that’s how I remember
Those fractional parts!