Today's Question:
Math

Does an acre have to have a specific shape? In The
Wall by Pink Floyd, the teacher says the area of an acre
is a rectangle that is one furlong in length and one chain in width.
How long is a chain and how wide is a furlong?

How do you convert Celsius to Fahrenheit?

I'm trying to visualize an acre. Is it about the size of a
football field?

I'm an auto mechanic, and I am trying to find a chart for
conversion from millimeters to fractions of inch. Can you help?

What are the Roman numerals for 50, 100, and 1,000?

We are trying to find feet measurement for an acre—not the
square footage. Can you please help?

I need to know about nautical knots. Before computers, how did
sailors measure them? Why are they called "knots" in the first
place?

In a recent academic competition, the students raised a question
about Roman numerals. I immediately referred to the 1998 Information
Please Almanac, and then to several other references, and could not
find an answer for them. The rules you cite are well
accepted and representative of what I have located in the texts. But,
here are the questions the students raised that seem to be beyond the
standard rules.
Even though 49 is typically written XLIX, is it also
acceptable to write it as IL?
Even though 400 is typically written CD, is it acceptable to
write it as CCCC?
Are there generally accepted rules which govern these
situations?

What is the measurement used by the military called a "click"?
Is it a mile? A tenth of a mile?

How long would it take to count to a billion?

What is the last digit of pi?

In diamond measurement, what is a carat?
Today's Question