unit 1-number system and rationals
absolute value -
A numbers distance from zero on the number line. We can use symbols to represent the absolute value of a number. For example, we can write the absolute value of 3 as | 3 | .
positive:
a number that has a value greater than 0.
negative:
a number that has a value less than 0.
positive number:
a number that is bigger than zero. A positive number can be written with a "+" symbol in front of it, or just as a number. For example, "+3" is a positive number. On a number line, positive numbers represent movement to the right.
negative number:
a real number that is less than zero. Negative numbers represent opposites. If positive represents movement to the right, negative represents movement to the left. Negative numbers are written with a "-" symbol in front. For example, "−3" is "negative 3"
integers:
a set of all whole numbers, and their opposites. {....-3, -2, -1, 0, 1, 2, 3...}
number line:
a straight line on which every point corresponds to a real number and every real number to a point.
rational number
any real number that can be written as a fraction
zero:
the integer denoted 0 means that no value is present. It is neither negative nor positive. A number which is not zero is said to be nonzero.
opposite:
two integers are opposites if they are each the same distance away from zero, but on opposite sides of the number line.