在GRE數學考試中，一般都假定以下信息為真：
●All numbers used are real numbers;
●All figures lie on a plane unless otherwise indicated;
●All angle measures are positive;
●All lines shown as straight are straight. On the computer-based test， lines that appear“jagged" can also be assumed to be straight (lines can look somewhat jagged on the computer screen)：
●Figures are intended to provide useful information for answering the questions. However，except where a figure is accompanied by a“Note" stating that the figure is drawn tO scale， solve the problem using your knowledge of mathematics， not by visual measurement or estimation.
細心的讀者會發現，上述假設實際上就是ETS 出題原則，即：
●所有的數都是實數;
●除非GRE數學題目中專門指出假設所有圖形都在同一個平面內;
●所有的角的測量值都是正數;
●所有顯示為直線的線均可當作直線來處理(在機試中，因為電腦顯示器的原因，直線可能會看起來呈“鋸齒狀”);
●伴隨問題的圖形將為解題提供有用的信息。但是，只有在GRE數學的問題中指出本圖形是按比例畫出(drawn to scale)時，才可以用目測或估計而得到的信息去解題。否則，只能運用你的數學知識去回答問題。這一解題原則可以簡稱為“只能讀圖，不能度量”的原則。