“You are crying,” stated a calm young voice across the table.

Brought up with a cool round turn, greatly mortified, Fifi thought that the best way to meet the emergency was just to say nothing.

“What is the matter?” demanded the professorial tones.

“Oh, nothing,” she said, winking back the tears and trying to smile, apologetically—­“just silly reasons.  I—­I’ve spent an hour and ten minutes on a problem here, and it won’t come right.  I’m—­sorry I disturbed you.”

There was a brief silence.  Mr. Queed cleared his throat.

“You cannot solve your problem?”

“I haven’t yet,” she sniffed bravely, “but of course I will soon.  Oh, I understand it very well....”

She kept her eyes stoutly fixed upon her book, which indicated that not for worlds would she interrupt him further.  Nevertheless she felt his large spectacles upon her.  And presently he astonished her by saying, resignedly—­doubtless he had decided that thus could the virginal calm be most surely and swiftly restored:—­

“Bring me your book.  I will solve your problem.”

“Oh!” said Fifi, choking down a cough.  And then, “Do you know all about algebra, too?”

It seemed that Mr. Queed in his younger days had once made quite a specialty of mathematics, both lower, like Fifi’s, and also far higher.  The child’s polite demurs were firmly overridden.  Soon she was established in a chair at his side, the book open on the table between them.

“Indicate the problem,” said Mr. Queed.

Fifi indicated it:  No. 71 of the collection of stickers known as Miscellaneous Review.  It read as follows: 

     71.  A laborer having built 105 rods of stone fence, found that if
     he had built 2 rods less a day he would have been 6 days longer in
     completing the job.  How many rods a day did he build?

Queed read this through once and announced:  “He built seven rods a day.”

Fifi stared.  “Why—­how in the world, Mr Queed—­”

“Let us see if I am right.  Proceed.  Read me what you have written down.”

“Let x equal the number of rods he built each day,” began Fifi bravely.

“Proceed.”

“Then 105 divided by x equals number of days consumed.  And 105 divided by x — 2 equals number of days consumed, if he had built 2 rods less a day.”

“Of course.”

“And (105 / x — 2) + 6 = number of days consumed if it had taken him six days longer.”

“Nothing of the sort.”

Fifi coughed.  “I don’t see why, exactly.”

“When the text says ‘six days longer,’ it means longer than what?”

“Why—­longer than ever.”

“Doubtless.  But you must state it in terms of the problem.”

“In terms of the problem,” murmured Fifi, her red-brown head bowed over the bewildering book—­“in terms of the problem.”