Racional: rational
Racionalizar: to rationalize
Radián: radian
Radical: radical
Radio: radius
Raíz: root
Raíz cuadrada principal: principal square root
Rango (recorrido): range of data
Rápido: fast
Ratio: ratio
Razón: reason
Razón de descuento: discount rate
Razón de incrementos: rate of increments
Razón unitaria: unit rate
Razonar: to reason out
Razones relacionadas: related rates
Reagrupar: to regroup
Realizar: to carry out
Recíproco: reciprocal
Reconocer: to recognize
Recordar: to remember
Recorrer: to travel over
Recta: line
Recta numérica: number line
Rectángulo: rectangle
Recto: straight
Recurso: resource
Redondear: to round off
Redondeo: rounding
Reducir: to decrease, to reduce
Reemplazar: to replace
Referencia: referente
Regla: rule
Regla (de medir): ruler
Regla de cálculo: slide rule
Regular: regular
Relación: relation
Relacionado: related
Repasar: to review
Repetir: to repeat
Representación: representation
Representar: to represent
Requisito: requirement
Requisitos previos: prerequisites
Residuo: residual
Resolución de ecuaciones: resolution of equations
Resolver: to figure out
Resolver: to resolve
Responder: to answer
Responsable: responsible
Respuesta: answer
Resta: subtraction
Restante: remaining
Restar: to subtract
Resto: remainder
Resultado: result
Resultante: resulting
Resumen: summary
Resumir: to summarize
Rombo: rhombus