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About This Quiz

Math: It's a word to strike fear into the hearts of many. But this much-maligned school subject is actually the mother of all the sciences -- none of them could exist without it -- and it's also very important to everyday life. Let's face it,Â America has a double standard when it comes to illiteracy and "innumeracy." No one would be proud of a friend who said, "I hate books; I can barely read, and never do it if I don't have to." Yet we readily give ourselves and other people a pass for not knowing the most basic mathematic concepts, ones that allow us to calculate a 15 percent tip on a restaurant bill or figure out how many gallons of gas we'll need for a road trip.Â

Where do you fall on this spectrum? To help you figure it out, we've created a quiz covering concepts from high school math classes, mainly algebra and geometry. You won't need a calculator for this one -- and, honestly, shouldn't use one -- though in places a pencil and paper might be handy.Â

Are you ready to stare down the dragon of your school days, and proudly prove your "numeracy"? Sharpen up your No. 2 pencil and get to it!

Which of these is a prime number?

5

A prime number is only divisible by itself and 1. Other prime numbers include 7, 11 and 17. They get rarer the farther you get from zero.

In its most basic definition, "x" in algebra stands for what?

a decimal

a rational number

a positive number

an unknown number

"X" is an unknown number. In some equations, other letters may be pressed into service as other unknowns -- but "x" is always the first choice. It's where we get phrases like "X factor" or titles like "The X Files."

Which of these is one-third expressed as a decimal?

.111

.333

Technically, the 3s should go on forever. This is because 1 can't be evenly divided by 3. Yet if you're dividing a cake into thirds, you can do it perfectly evenly. (Don't think about this too long; your brain will melt).

Fractions consist of a numerator and a denominator. Fun fact: "denominator" has taken on a meaning in everyday English, in the expression "the common denominator," meaning something that unites seemingly different things or people. "Numerator" has no such casual use.

"Degree" is a flexible word in the English language. We also use it to measure heat, to put a ranking on academic achievement (a master's degree), and to describe an undefined "certain amount" of something ("If you had even a degree of sympathy ...") And, of course, they're vital to geometry.

Circles are perfectly round, but mathematicians think of them as implicitly divided up into any number of angles, from the center to any two points on the circumference. This is how we get compass readings, from 1 degree to 360 (or 0 to 359, if you prefer to count that way).

Squares and cubes are part of a system called _______.

number rationality

number irrationality

artistic notation

scientific notation

Science often deals with very large numbers, and scientific notation makes them easier to manage. For example, in astronomy, it's easier to represent vast distances in light years using 10 and a superscript number than to write it out.

In scientific notation, the number in superscript is called the ______.

deponent

exponent

The word "exponent" has been hijacked by people who enjoy superlatives. "This stock is about to take off exponentially!" or "After I started reading Jordan Peterson, I saw exponential growth in my personal life!" Note to everyone: "exponential" does not just mean "a lot."

Euclid said it best: "A point is that which has no part." He meant it was a theoretical concept. Likewise, a "line" in geometry has no specified measurement, either.

From a single point, you could move off in any direction. But just one other point, and suddenly you've got a line -- you can predict its path indefinitely. Just two points! Like a designer once said, "Simplicity is the ultimate style."

If one interior angle of a triangle is 75, what is the sum of the other two angles?

90

105

We covered this in an earlier question: The sum of the three interior angles of a triangle always add up to 180 degrees. Just wanted to see if you were paying attention!

Angles are classed as "acute" (less than 90 degrees) and "obtuse." Fun fact: Outside math, these words are generalized to mean "sharp" and "dull." At the emergency room, you might be asked if your pain is "acute." In the dating world, if you can't see that someone's just not that into you, you're being "obtuse."

Once an angle goes past 179 degrees to 180, well, it's a line. Beyond that, and it's an angle from the other direction (it might help to actually draw this on a piece of paper, to visualize it).

A chord going directly across a circle at its widest point (e.g. 90 to 270) is called the ____.

dianthus

diameter

The diameter is always twice the radius, and therefore can be used to find a circle's area. (Sidenote: If you chose "didjeridoo," wipe that smirk off your face; we know you knew better!)

When you write 8/10 as 4/5, you are reducing it to what?

the lowest common denominator

The denominator is the key here, not the numerator. 5 is the lowest the denominator can go without being split into a fraction/decimal itself. On the other hand, there are plenty of higher denominators possible -- 20, 40, 100. However, reducing fractions to the lowest common denominator is a more common task in math than raising them to a higher common denominator.

Like one-third, two-thirds would go on forever as a decimal: 0.666666 .... As a fraction, either 2/3 or 66/100 gets as close as you reasonably need to get.

In the simple equation 12 /4 = 3, 4 is the divisor. and 12 is the dividend. This is confusing because in everyday life, a "dividend" is the result of something being divided up: "The original investors shared the dividends."

What number would you divide the sum of this list -- 4, 12, 21, 24, 42 -- by to get the mean?

two

three

four

five

There are five numbers on the list, so you'd divide the sum by five. Or, put another way: 103 divided by 5 equals 20.6. So 20.6 is the mean, or average, in this list.

In the number 12.37859, which digit is in the hundredths place?

1

2

3

7

This confuses new learners: on the left of a decimal point, the first digit represents single numbers, and the next one left of that is the tenths place. But to the right, the first place is the tenths place, and the next one hundredths. So here, 7 is in the hundredths place.

A "pie wedge" of area inside a circle, defined by two radii, is called a/an ______.

circangle

anglogram

radian

sector

Frequently borrowed by sci-fi writers, "sector" is part of a circle. It's almost a triangle, but is not, because one side (the part defined by the circle's circumference), is curved.

Pi is an irrational number; it goes on forever without repeating patterns. By general agreement, it is represented only as 3.14. Some math lovers pride themselves on being able to recite pi to dozens or hundreds of digits. We do not claim to understand this.