The analogy is meant to show parallels between two sets of words. Fertile is to arable as vague is to clouded. If you understand either pair it can be used to decipher the meaning of the other pair you don't know.
And so is your teacher, isn't she?
Answer:
"How d-u-m-b can you get!" said Robert. "A co-l-o-s-s-a-l waste of time if you ask me. So get going! S-c-r-a-m! S-h-o-o!"
Explanation:
"The Number Devil: A Mathematical Adventure" is a book written by Hans Ma-g-n-us En-zen-s-ber-ger. The book is about a young boy named Robert, who does not like Mathematics, eventually meet a number devil, named Te-plot-a-xl. Te-plot-a-xl then teaches Robert maths over the period of twelve dreams.
The excerpt from the book which suggests that the sole purpose of Robert was to oppose the number devil is,
<em>"How d-u-m-b can you get!" said Robert. "A co-l-o-s-s-a-l waste of time if you ask me. So get going! S-c-r-a-m! S-h-o-o!"</em>
In this excerpt, he is seen chasing away the number devil.
