Types of Numbers Terms
Get down with the lingo
Absolute Value
The number's distance from 0 on a number line. The absolute value of a number x is denoted by |x|, and those bars always make what's inside turn positive:|x| = x
|-x| = x
So with absolute value, we're not concerned with whether x is positive or negative, we just want to know how far it is away from 0. Because 0 has had some problems with x in the past, and has applied for a restraining order.
Additive Identity
The number 0 is the additive identity, because if 0 is added to any number, the number doesn't change. Prime example: your mother has been adding 0 to her age for 12 years now, and she's still 29.Additive Inverse
The number that, when added to a given number, results in the additive identity (0). It's basically going to be the same number but with a negative sign removed or attached to the front of it. The additive inverse of x is -x, as x + (-x) = 0. So if you start with "hero" and add "-hero," you can go from hero to zero.Associative Property
The sum and product of three or more numbers is the same no matter how you group them. For example:(a + b) + c = a + (b + c) and (a × b) × c = a × (b × c)
Unfortunately, this doesn't work with subtraction or division. They're a little more rebellious. They dare to be different.
Commutative Property
The sum and product of three or more operands (the numbers on which an operation is performed) is the same no matter how you order them. For example:(a + b) + c = (b + c) + a and (a × b) × c = (c × b) × a
For the commutative property, think "commute," like your commute to and from school. Doesn't matter how many times you go back and forth or what different routes you take, you keep ending up back at the same place.
Decimal
Representation of a number using base 10. If you have an extra finger, try using base 11.Denominator
A fraction's bottom. The fraction will usually try to keep this part of him covered up, but his mother will usually produce some scandalous baby picture of him in the tub where his denominator is clearly visible.Distributive Property
Multiplication of numbers distributes over addition and subtraction:a (b ± c) = ab ± ac
And so you see, the distributive property has nothing to do with Socialism. You were so worried.
Dividend
A number that is to be divided by another number. Apparently, this other number got hold of a butcher's knife.Divisor
The number which a dividend is divided by. Or, the number doing the dividing. Whichever way makes the most sense to you. Either way, there's going to be some good old-fashioned dividing going on.Equivalent Fraction
Two fractions that have the same value but are represented differently. For example, 1/2 and 11/22 are equivalent. If you and your sister decide to go splitsies on a burger, don't think you're getting any more than half just because she offers you 11/22 of it.Even Number
An integer that's divisible by 2. Your friend Steve who's turning 18 next month? He'll soon be an even Steven. (Right now, he's a little odd.)Exponentiation
Part of the word "Supercalifragilisticexponentiation." Okay, okay, you called our bluff. It's the mathematical operation of raising a number a to a power (exponent) n.a^{n} = a × a × … × a (n times)
Josh Groban sings an inspiring tribute to the power of exponents. You may be familiar with it.
Factor
A number that divides evenly into another number. For example, 8 and 3 are factors of 24. Oh great—now we're really gonna hear it from 2, 4, 6 and 12. We said for example. Sheesh.Factorization
Expressing a number as the product of its factors. This is just a way of breaking a number down into smaller numbers so that you can easily tell what factors it has in common with another number. If two numbers have a lot of factors in common, you can try setting them up on a date. Matchmaker, matchmaker, make me a match.Keep in mind that factorization is not unique. For example, 24 can be factorized as 8 × 3 or 6 × 4. So in a single day, you could either watch Gandhi 8 times or Gone With the Wind 6 times. Either way, you'll never want to see either of those movies ever again.
Finite Decimal
A decimal number that has a finite number of decimal places. Get outta here, pi. This has nothing to do with you.Fraction
The ratio of two numbers or variables. 1/2 is the most famous of all the fractions. It lives in the Hollywood Hills and has its own driver.Googol
The number 10^{100}, or the number 1 followed by 100 zeros. Don't even think about trying to Google "googol." Your computer will explode.Greatest Common Factor (GCF)
The largest positive integer that divides evenly into two or more non-zero numbers. For example, the GCF of 18 and 24 is 6.It's also known as the greatest common divisor or highest common factor. It goes by many names, and has a different passport for each. How Jason Bourne is that?
Imaginary Number
A number that, when squared, gives a negative real number. The imaginary unit is i, defined as i^{2} = -1. Since any number multiplied by itself will always give you a positive result, this number had to be made up.What's that? You say you can see the number i typed out in the preceding sentence? Shh—you're imagining things. Just go back to sleep.
Improper Fraction
A fraction that tells bawdy jokes in mixed company.Oh, all right. You're no fun. An improper fraction is one in which the numerator is larger than the denominator, like 13/5 or 25/4. These can be expressed as mixed numbers. Keeping with the examples, these fractions could be written as 2 3/5 and 6 1/4, respectively. There, now our fractions aren't so top-heavy.
Infinite Decimal
A nonterminating decimal representation of real numbers. Wha-huh? Basically, in an infinite decimal, the numbers after the decimal point continue on forever. Perpetually. Without end. Ceaselessly. Ad infinitum. Evermore. Like this catalog of synonyms.You've got two kinds of infinite decimals—recurring or repeating (if the denominator in the rational number has any prime factors other than 2 or 5, for example: 1/3=0.333…) and nonrecurring (decimal representation of irrational numbers). You may notice that these are also your DVR recording options. No connection.
Infinity
If you've seen any of the Toy Story movies, you should know what infinity is. That's where Buzz Lightyear is headed. (And beyond, obviously.) In short, infinity is the concept of a quantity that is endless and unbounded. Its symbol looks like an "8" drank too much Nyquil and tried to find its way to the bathroom in the dark (∞).Integer
The natural numbers (1, 2, 3, 4...), their negatives (...-4, -3, -2, -1), and zero. These are the numbers that are the easiest to work with. Some of those fractions and decimals have severe social disorders.Irrational Number
A number that feels safer in a car than on an airplane, even though statistics clearly indicate that you're much more likely to be in an automobile accident than a plane crash.Also, it's a real number that cannot be expressed as a fraction ^{p}/_{q}, where p and q are integers. Irrational numbers don't have finite or repeating decimal representation. For example the square roots of 2, π, and e are irrational numbers. If you think about it, it's pretty irrational to expect anyone to be able to write out something that has an infinite number of decimal places.
Least Common Multiple (LCM)
The smallest integer that is a multiple of two or more integers. For example, the LCM of 4 and 6 is 12. If you take 36, on the other hand, it's a multiple of both numbers, but it is not the least common multiple. Don't get down on yourself, 36. You'll have your day in the sun.Lowest Common Denominator (LCD)
The least common multiple (LCM) of the denominators of two or more fractions. For example, the LCD of 3/4 and 5/18 is 36. What did we tell you, 36?!Lowest Term
A fraction is in "lowest terms" when the only common factor of the numerator and denominator is 1. This should make sense, because if they shared a common factor, they could be simplified further. You may see the glass as 13/26 empty, but we see it as 1/2 full.Mixed Number
A number expressed as a whole number and a fraction, like 2½ or 4¾. You'd never be able to bake a cake without these bad boys.Multiple
The product of any number and an integer. For example, 0, -6, 12, and -72 are multiples of 6, whereas 15 and -32 are not. Be careful of where you put your multiple, because you don't want to be accused of dodgy product placement.Multiplicative Identity
The number 1. That's a pretty fancy way of just saying "1," isn't it? Yes, we suppose so. What the term means is that if 1 is multiplied by any number, that number doesn't change. However, let's not make a big deal about how ineffectual he is. He's a little sensitive about it.Multiplicative Inverse
The non-zero number that, when multiplied by a given non-zero number, results in the multiplicative identity 1. The multiplicative inverse of x (x ≠ 0) is ^{1}/_{x} because:x(^{1}/_{x}) = 1
This is not to be confused with the Multiplicative Converse, which says that when you multiply one Chuck by 2, you get a pair of Chucks.
Natural Numbers
These are numbers that walk about unclothed in an effort to rebel against the constraints of society.Okay, so they're not that natural. Natural numbers are those in the set of positive integers {1, 2, 3...}. Any time you're counting a number of real-life objects, you're using exclusively natural numbers to do so. Unless you have zero of something. In which case, why are you bothering to count? Zero. There—you're done.
Number Line
A straight line on which every point corresponds to a real number. Sometimes it's hard keeping all of those numbers in a single straight line, especially when one of them suddenly has to use the bathroom.Numerator
The top part of a fraction."I'll be back... on top of the denominator." - Numerator II: Judgment Day