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.