33 terms

# Math Vocab lessons 13-30

#### Terms in this set (...)

elapsed time
length of time between two events
positive numbers
numbers greater than zero
numbers to the right of zero on a number line
negative numbers
numbers less than zero
numbers to the left of zero on a number line
zero
neither negative nor positive
opposites
two numbers whose sum is zero
-3+3=0
integers
all of the counting numbers and their opposites, as well as the number zero
estimate
a quick way to "get close" to the answer
mixed number
numbers containing fractions
average
number found when the sum of two or more numbers is divided by the number of addends in the sum; also called the mean
factors
the whole numbers that divide a given number without a remainder
prime numbers
numbers that have exactly two factors: the number 1 and the number itself
greatest common factor
the largest whole number that is a factor of two or more given numbers
divisibility tests
help us find the factors of a number - see pg 108 to learn divisibility tests
ratio
the way to describe a relationship between numbers
multiples
product of a natural (called counting by book) number and another number
reduces
to rewrite a fraction in lowest terms
circumference
distance around a circle
diameter
distance across a circle through its center
distance from the center of a circle to the side of a circle
compass
tool for drawing a circle
concentric circles
circles within the same center like a bulls-eye target
plane
a flat surface
intersect
when lines cross
perpendicular
when 2 lines intersect and make square, 90 degree square angles
parallel
when lines do not cross but stay the same distance apart
oblique
lines that intersect but are not perpendicular
Vertex
the point where rays of an angle originate
right angle
the square angles formed by perpendicular lines, rays or segments
obtuse angles
angles that are greater than 90 degree right angles
acute angles
angles that measure less than right, 90 degree angles
least common multiple
the smallest whole number that is a multiple of two or more given numbers
reciprocals
two numbers whose product is 1
ex: 2 x 1/2 = 1
term (in a fraction)
a number that serves as a numerator or denominator of a fraction