Everyday Mathematics Parent Handbook

Glossary for Everyday Mathematics

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M
magnitude estimate (4) An estimate of whether a solution is in the tens, hundreds, thousands, or more. map legend (4) A diagram that explains the symbols, markings, and colors on a map. Also called a map key.
map scale (3) A rate that compares the distance between two locations on a map with the actual distance between them. The rate is often represented by a labeled line segment, similar to a ruler.
mathematics (1) A study of relationships among numbers, shapes, and patterns. Mathematics is used to count and measure things, to discover similarities and differences, to solve problems, and to learn about and organize the world. mean (average) (3) A typical or middle value for a set of numbers. It is found by adding the numbers in the set and then dividing the total by the number of values in the set. Example: 2, 4, 5, 9, 10 = 30; 30 ÷ 5 = 6; The mean is 6. median (3) The middle value in a set of data when the data are listed in order from smallest to largest (or largest to smallest). If there is an even number of data points, the median is the mean of the two middle values. Example: 2, 3, 4, 6, 10 - the median is 4 because it is the middle value. memory keys (2) The [M+], [M-], and [MRC] calculator keys. The [M+] key is used to add a number to the number stored in the calculator's memory; the [M-] key is used to subtract a number from the number in memory. The [MRC] key, pressed once, displays the number currently stored in memory; when the key is pressed twice, the calculator's memory is cleared. meridian bar (4) A device on a globe that shows degrees north and south of the equator. meter (m) (1) In the metric system, a unit of length equal to 10 decimeters, 100 centimeters, or 1000 millimeters. metric system (1) A measurement system based on the base-10 numeration system and used in most countries in the world. Units for linear measure (length, distance) include millimeter, centimeter, meter, kilometer; units for mass (weight) include gram and kilogram; units for capacity (amount of liquid or other pourable substance a container can hold) include milliliter and liter. middle value (1) The number in the middle when a set of data is organized in sequential order; also the median. millimeter (mm) (3) In the metric system, a unit of length equal to 1/10 of a centimeter or 1/1000 of a meter. mixed number (4) A number that has a whole number part and a fraction part. Example: 2 is equal to 2 + . mode (2) The value or category that occurs most often in a set of data. multiples (1) Multiples of numbers are the product of that number and whole numbers. Example: 45 is a multiple of 5 because 45 = 5 x 9. multiplication (2) An operation used to find the total number of things in several equal groups. Numbers being multiplied are called factors. The result of multiplication is called the product. In 5 x 12 = 60, 5 and 12 are factors. 60 is the product. Division "undoes" multiplication: = 12 and = 5.
N
name-collection box (1) A box-like diagram containing a number, used for collecting equivalent names for that number.
negative number (1) A number less than (below) 0. net score (4) The final score of a turn or game after any operations have been done. Example: In the game of Factor Captor, your first move is 29, your opponent's move is 1. You get your net score, 28, by subtracting 1 from 29. net weight (3) The weight of the contents of a container without including the weight of the container. nonagon (3) A nine-sided polygon. number line (1) A line on which points correspond to numbers. number model (1) A number sentence that shows how the parts of a number story are related. Example: 5 + 8 = 13; 27 - 11 = 16; 3 x 30 = 90; = 7. number sentence (1) A sentence that is made up of numerals and a relation symbol (=, <, >). Most number sentences also contain at least one operation symbol (+, -, x, ÷). number story (K) Story problems; word problems that put numbers and number relationships into a real world context. numerator (1) The top number in a fraction. The number of equal parts being considered when a whole is divided into equal parts. In the fraction, a is the numerator.
O
obtuse angle (4) An angle greater than 90 degrees and less than 180 degrees.
octagon (1) An eight-sided polygon. odd number (2) A whole number that is not evenly divided by 2, such as 1, 3, 5, and so on. When an odd number is divided by 2, the remainder is 1.
opposite of a number (4) A number that is the same distance from zero on the number line as the given number, but on the opposite side of zero.
ordered pair (3) Two numbers in a specific order used to locate a point on a coordinate grid. They are usually written inside parentheses: (2,3). The horizontal coordinate x is given first; the vertical coordinate y is given second. ordinal number (1) A number used to express position or order in a series, such as first, third, tenth.
origin (1) The point where the x-axis and y-axis intersect on a coordinate grid.
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