#number
13 concepts
Concepts
Natural Numbers
Positive integers used for counting: 1, 2, 3, 4, ...
Integers
The set of numbers including positive integers, zero, and negative integers.
Rational Numbers
A number that can be expressed as a ratio (fraction) of two integers.
Irrational Numbers
A number that cannot be expressed as a fraction, with infinite non-repeating decimal expansion.
Real Numbers
The set of all rational and irrational numbers, corresponding to every point on the number line.
Prime Numbers
A natural number greater than 1 that has no positive divisors other than 1 and itself.
GCD and LCM
GCD (Greatest Common Divisor) is the largest number that divides both numbers. LCM (Least Common Multiple) is the smallest number divisible by both.
Fractions
A number representing part of a whole divided into equal parts.
Decimals
A number written using a decimal point to represent fractional parts as powers of ten.
Percentages
A ratio expressed as a fraction of 100.
Ratios
A comparison of the relative sizes of two numbers, written as a:b or a/b.
Proportions
An equation stating that two ratios are equal.
Complex Numbers
A number combining real and imaginary parts, written as a + bi where i² = -1.