German to English Science Mathematics & Statistics

This is a term used in a book on mathematics. Under the heading "Distributivgesetz" is the following:

Manchmal ist es am einfachsten, eine Rechnung in zwei Rechnungen aufzuspalten, wie etwa im Beispiel 4 x 18 = 4 x (10 + 8) = 4 x 10 + 4 x 8 = 40 + 32 = 72.
algebraisch; a x (b + c) = a x b * a x c = ab + ac (Kurzschreibweise)
Darstellung mit Rechteckflächen

There is then a picture of a rectangle divided in two horizontally with the line on the LHS marker "a", the two sides along the bottom marked "b" and "c" and inside one side of the rectangle is "ab" and the other "ac".

The best I have found for "Rechteckflächen" is "rectangle statement". What I need, please, is either confirmation that this is correct, or a better term if it is not.