M

Mass   The measure of the amount of matter an object contains.

Mean   The value found by dividing the sum of a group of numbers by the number of numbers in the group.  Also called average.

Means of a proportion   The second and third terms of a proportion.

Measure of central tendency A number used to represent all the numbers in a set of data.  Three such measures are the mean, the median, and the mode

Median   The number that falls in the middle when data are listed from least to greatest.  If the number of data is even, the median is the mean of the two middle

Meter The unit of measure for length in the metric system

Metric system A system of measures based on powers of ten

Midpoint   The point of a segment that divides it into two congruent segments.

Mixed number     A whole number plus a proper fraction.

Mode   The number that occurs most often in a set of data.

Multiple A multiple of a whole number is the product of that number and any whole number

Multiplicand The second factor in a multiplication problem

Multiplicative inverse Two numbers are said to be multiplicative inverses of each other if their product is one

Multiplier The first factor in a multiplication problem

n , n¸1 = n

n, 0 x n= n x 0=0

n, n + 0 =0 + n

n,1 x n = n x 1 = n