Definitions
Numbers
|
Even Numbers
|
numbers divisible by 2
|
2,4,6,... |
|
Odd Numbers |
numbers not divisible by 2
|
1,3,5,7,... |
|
Whole Numbers
| 0,1,2,3,4,..... |
- Integers include the whole numbers, but extend the range to include negative numbers.
- Prime Numbers are numbers with no factors other than 1 and the number itself.
- Rational Numbers are numbers that can be represented as a fraction. Integers
come under this classification because, for example
\[ 12 = \frac{12}{1} \] - The Reciprocal of a number is given by
\[ \mbox{reciprocal} = \frac{1}{\mbox{number}} \] For example :
The reciprocal of 3 is \(\frac{1}{3}\)
The reciprocal of 0.362 = \(\frac{1}{0.362}\)
Operations
- The Sum of two numbers is the result of adding them
- The Difference of two numbers is the result of subtracting the smaller number from the larger number
- The Product of two numbers is the result of multiplying them
- The Binary Operators are +, -, x , and \(\div\)
- An operation is Commutative if the order does not matter. Addition and multiplication are commutative, subtraction and division are not.
- A Factor of a number is a number that divides that number exactly.
Fractions
- The top part of a fraction is called the Numerator
- The bottom part of a fraction is called the Denominator
Prime Numbers
A prime number is a number that can only be divided by 1 and itself.
For example : 3, 5, 7, 11, 13, 17, 19
- 1 itself is not included as it does not have two factors.
Note
- The only even prime number is 2
- A product of prime numbers is, by definition, not itself a prime number
Shapes
Shapes with all sides equal are called regular. Otherwise they are called irregular.
Shapes with 3 sides are called triangles. Regular triangles are called equilateral.
Shapes with 4 sides are called rectangles. A regular rectangle is called a square.
Four-sided figures with two pairs of parallel sides are called parallelograms