Simplify the following text for a Grade 10 native English-speaking person.
Original: In classical mechanics , moment of inertia , also called mass moment of inertia , rotational inertia , polar moment of inertia of mass , or the angular mass , ( SI units kgÂ mÂ ) is a measure of an object 's resistance to changes to its rotation .
Simplified: Moment of inertia , also called mass moment of inertia , is the rotational analog of mass.