Drawings

What an interesting illustration!! I've never encountered anything like it! After doing some research and in consultation with another tactile expert, I would recommend that you do present this as a tactile graphic.
Is this the only occurrence within the textbook? Has the use of the circles, oval, and square been explained elsewhere? Is the student asked to use this method in their work?
It seems to me that the square represents the "missing number" referred to in the question. And, that it is a "fast-array" because instead of showing the complete array, it combines the use of numbers along with the shapes from one row and one column of what the complete array would look like. i.e. In question 1, there are 8 circles representing the number of rows, and 9 circles representing the number of columns. (What I originally took for the number 28 in question 2, is actually 2 small circles with the number 2 placed beside them. If the transcriber is familiar with this type of drawing, this erroneous thinking would not occur!) The "missing number" would be the total number of circles in the complete array.
The use of the oval is not as clear. I assume that it indicates the method of solving the question, rather than indicating that there are too many circles to draw. Questions 2 and 3 involve division, rather than multiplication, to solve.
If anyone else has any insight on this type of illustration, please comment. It is my opinion that they should be done as a tactile, but they are certainly new to me. Perhaps others can shed further light on the subject.

These 3-D shapes occur often in math textbooks, and hopefully when they are transcribed consistently the students get used to reading them. It also helps if they have used classroom manipulatives when first learning the various shapes. You are on the right track by using solid lines for the outline and dashed lines for the "invisible" lines. Sometimes in print the basic shape (usually the base) is shaded, or a heavier outline can assist in drawing attention to the basic shape. I always change the orientation so that the 3-D perspective is to the right, with the basic shape parallel to the page rather than skewed. I have attached a 2-page file of several examples you may wish to refer to.
Hope this helps!
Betty