Question

Explain why it is necessary to rename 4 1/4 if you subtract 3/4 from it

Answer 1

You would rename four and one fourth when subtracted from three fourths because when you subtract the fractions you get a different fraction for your answer.
$4 \frac{1}{4}- \frac{3}{4}= 3 \frac{1}{2}$
so you would said three and one half instead of four and one fourth.
Hope I helped!