A Glossary of Mathematical Terms - R
Range
In a set of data it is the difference between the largest and the smallest value of data.
Ratio
The quotient of two quantities.
Reciprocals (Multiplicative inverses)
Two numbers whose product is 1.
Reduction of a fraction
The process of finding and removing all common factors between the numerator and the denominator.
Reflection
See Flip.
Reflex (Concave)
Remainder
The difference of the dividend and the greatest multiple of the divisor, which is less than the dividend.
Repeating decimal
A decimal like 2.343434...
Rhombus
A quadrilateral with equal sides.
Root
Of an equation;
of a quantity (square root, cube root, ...).
Round brackets ( )
See Parenthesis.
Rounding
A process that replaces a number with a value closest to the original, but with a specified number of decimal places or digits: 37.39 rounded to the nearest tenth is 37.4; 123 rounded to the nearest ten is 120.