Dictionary
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 decimal number
 A fraction where the
denominator is a power of ten and is therefore expressed using a decimal
point. For example: 0.37 is the decimal equivalent of 37/100 (cfDecimals Discussion).
 degrees
 A circle is measured in units called degrees. The entire circle is 360 degrees,
half a circle is 180 degrees, and one quarter of a circle is 90 degrees.
The "L"
shaped 90 degree circle forms what is called a right angle. When examining circular
objects, such as spinners, the size of each segment in the circle can be described in
degrees (cf From Geometry to Probability Discussion).
 denominator
 In a rational number,
the number below the fraction bar that indicates how many parts the whole is divided into. See also numerator (cfFractions
Discussion, Adding and
Subtracting Fractions Discussion, Multiplying
and Dividing Fractions Discussion, Comparing Fractions
Discussion, and Percents
Discussion).
 discontinuous graph
 A line in a graph that is interrupted, or has breaks in it forms a discontinuous
graph
(cf Impossible Graphs Discussion).
 disjoint events
 Two events are disjoint if they can't both happen at the same time (in other words,
if they have no outcomes in common). Equivalently, two events are disjoint if their
intersection is the empty set.
 distributive property
 Summing two numbers and then
multiplying by another number yields the same value as multiplying both values by the
other value and then adding. In mathematical terms, for all real numbers a, b, and c,
a(b+c) = ab+ac.
 division
 The inverse operation of multiplication (cf
Integer Division Discussion,
Fraction Multiplying and Dividing Discussion).
 domain of the function f
 The set of numbers x for which f(x) is defined.
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