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.