PRAXIS II: MATH CONTENT
These are not official mathematics definitions.
Cardinal number |
a count of how many ( 4 ducks) |
Ordinal number |
position (2nd duck in the row) |
Nominal number |
Relative position such as a house number. Does not indicate number before it as does the ordinal number. Also identifiers such as numbers on athletic jerseys. |
Distributive property |
Distributes multiplication over addition or subtraction. 2( x+4) = 2x+8 |
Commutative property |
A change in order does not affect the outcome. Multiplication and addition, but not for subtraction or division. A+B=B+A and A*B=B*A |
Associative Property |
A change in grouping but not order. Addition and Multiplication but not division or subtraction. A + (B+C) = (A+B)+C and A*(B*C)=(A*B)*C |
Prime number |
Only factors are 1 and itself 2 ,3 ,5, 7, 11, 13, etc |
Composite number |
Factors in addition to 1 and itself 4, 6, 8, 9 etc |
GCF |
Greatest Common Factor: Largest number that will divide into 2 or more numbers Example: 4 is the GCF of 8 and 12 |
LCM |
Least Common Multiple: Smallest number that 2 or more numbers will divide into. Example: 24 is the LCM of 8 and 12. |
Order of operations |
Powers, multiplication and division, addition and subtraction unless otherwise indicated by parentheses. |
Reciprocal |
The product of a number and its reciprocal is 1. The reciprocal of a/b is b/a. |
Algorithm |
A routine process used to obtain a result to a problem. |
Pascal’s Triangle |
A triangular array of numbers representing the coefficients of a binomial expansion. |
Series |
A list of numbers with a common definition. Example: the odd or even numbers, prime numbers, Fibonacci numbers. |
Arithmetic Series |
Not all series are arithmetic or geometric, but arithmetic and geometric are two common series of numbers. An arithmetic series is a series with a common difference between terms, e.g., 3, 7, 11, 15, 19,… a1 is the first term ( 3), d is the difference between terms (4) and n is the number of the term (the fourth term: a4 is 15 in this case) The general rule for finding a term is an = a1 + d(n-1). If we want the 10th term: a10 = 3 + 4(9) thus a10 = 39 for this series of numbers. |
Geometric Series |
A geometric series is a series with a common factor between terms, e.g., 3, 6, 12, 24, 48,… or 8, 4, 2, 1, ½, ¼, 1/8, … Once again the first term is a1, n is the number of the term, and r is the common factor between terms. In the first example, r = 2 and in the second example r = 1/2 . The general rule for finding a term is an = a1r(n-1) For example from the first series a8= 3(2)7 thus the 8th term is 3(128) which equals 384. |
Sequence |
The sum of a series. Example: sum of the odd numbers 1 thru 7 is 16. |
Perpendicular |
Lines meeting to form right angles |
Parallel |
Coplanar lines which do not intersect. Planes that do not intersect |
Transformations |
Common transformations in Geometry are the Rotation (turn), Reflection (flip) (how it would appear in a mirror), and the Slide. |
Common System of Measurement |
Common units: inches, feet, yards, miles, pints, quarts, gallons, ounce, pound, ton, and degree Fahrenheit. These used to be called the English System of Measurement. |
Metric System of Measurement |
Common units: meters, liters, grams, and degree Celsius. Used with common prefixes of milli, centi, kilo. |
Mean |
Most commonly used measure for average. Sum of terms divided by number of terms. The value if all terms were the same. |
Median |
Less commonly used measure of average. Middle term in a list of ordered terms. Example: Seven is the median of 1, 4, 7, 8, 9 |
Mode |
Least commonly used measure of average. Most frequently appearing item or number in a list of terms. Example: 3 is the mode for 1,1,3,3,3,3,5,6,6,7,8,9,9 |
Weighted average |
Mean calculated after some scores a given more value than others. Example: test grades may count for two grades. |
Range |
Highest score minus lowest score. Also can be defined as highest score minus lowest score plus one. The latter form is rare. |
Additive Inverse |
Number added to another number to get zero. Example -3 and 3 |
Multiplicative identity |
A number multiplied by something to make the result one. The product of a number and its reciprocal. Example: 3 and 1/3 |
Scalene triangle |
No sides the same length |
Isosceles triangle |
Two sides the same length |
Equilateral triangle |
Three sides the same length. Also is equiangular. |
Acute triangle |
All angles are less than 90 degrees |
Obtuse triangle |
One angle is greater than 90 degrees |
Right triangle |
One angle is 90 degrees |
Volumes Cylinder or Prism: |
V = Bh (B is area of the base and h is the height) Example: Rectangular Based Prism: V=lwh. Triangular Based Prism: V=1/2(abh). Cylinder: V=πr2h. |
Volumes Cones and Pyramids |
V = 1/3 Bh (B is area of the base and h is the height) Example: Rectangular Based Pyramid: V=1/3 lwh. Triangular Based Pyramid: V=1/3(1/2abh). Cone: V=1/3(πr2h). |
Factor tree |
Simple diagram of prime factors of a number. |
Celsius to Fahrenheit |
F = 9/5(C) + 32 |
Fahrenheit to Celsius |
C = 5/9(F -32) |
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NOTE: -40 degrees C is equal to -40 degrees F |