Glossary: Terms Starting with R

railway

MathsFrom Grade 4

Two rails in parallel.

Learn it in: Parallel lines (Grade 4)

range

MathsFrom Grade 4

Greatest minus least.

Learn it in: Line plots (Grade 4), Comparing datasets (Grade 4), Frequency tables (Grade 5)

rate

MathsFrom Grade 6

Ratio with different units.

Learn it in: Unit rates (Grade 6), Mathematical modelling (Grade 6)

ratio

MathsFrom Grade 6

Comparison of two quantities.

Learn it in: Understanding ratios (Grade 6), Ratio word problems (Grade 6)

ratio table

MathsFrom Grade 6

Table of equivalent ratios.

Learn it in: Ratio tables (Grade 6)

ray

MathsFrom Grade 4

Starts at one point and goes on forever.

Learn it in: Rays (Grade 4), Points and lines (Grade 6)

reasonable

MathsFrom Grade 3

Makes sense.

Learn it in: Estimation (Grade 3), Estimation (Grade 4), Checking reasonableness (Grade 4)

recipe

MathsFrom Grade 6

Ingredient instructions.

Learn it in: Real-world applications (Grade 6)

reciprocal

MathsFrom Grade 6

Flip a fraction.

Learn it in: Dividing fractions (Grade 6)

record

MathsFrom Grade 1

Write down.

Learn it in: Simple tally marks (Grade 1), Collecting data (Grade 2)

rectangle

MathsFrom Grade 1

A shape with 4 straight sides and 4 square corners.

Learn it in: Rectangles (Grade 1), Perimeter (Grade 4)

rectangular prism

MathsFrom Grade 5

Box shape.

Learn it in: Unit cubes (Grade 5)

reflection

MathsFrom Grade 3

A mirror image.

Learn it in: Symmetry (Grade 3), Symmetry (Grade 4), Plotting points in four quadrants (Grade 6)

regroup

MathsFrom Grade 2

Exchange 10 of one place for 1 of the next.

Learn it in: Regrouping in addition (Grade 2), Regrouping in subtraction (Grade 2), Addition with regrouping (Grade 3)

regular

MathsFrom Grade 6

All sides and angles equal.

Learn it in: Polygons (Grade 6), Perimeter (Grade 6)

regular polygon

MathsFrom Grade 4

All sides and angles equal.

Learn it in: Symmetry (Grade 4), Properties of polygons (Grade 5), Perimeter (Grade 5)

relationship

MathsFrom Grade 4

How numbers connect.

Learn it in: Number relationships (Grade 4)

remain

MathsFrom Grade 1

What is left over.

Learn it in: Taking away objects (Grade 1), Finding how many remain (Grade 1)

remainder

MathsFrom Grade 3

What is left over after dividing.

Learn it in: Division with remainders (Grade 3), Division word problems (Grade 3), Division with remainders (Grade 4)

remaining

MathsFrom Grade 4

What is left.

Learn it in: Fraction word problems (Grade 4), Fraction word problems (Grade 5)

repeat

MathsFrom Grade 1

Happen again and again.

Learn it in: Recognising patterns (Grade 1)

repeated addition

MathsFrom Grade 2

Adding the same number again and again.

Learn it in: Repeated addition (Grade 2), Multiplication as equal groups (Grade 3), Area of rectangles using arrays (Grade 3)

repeated subtraction

MathsFrom Grade 4

Subtract the divisor again and again.

Learn it in: Division strategies (Grade 4)

represent

MathsFrom Grade 1

Show a number in a picture, a model or words.

Learn it in: Representing two-digit numbers (Grade 1)

rhombus

MathsFrom Grade 3

4 equal sides.

Learn it in: Quadrilaterals (Grade 3), Quadrilaterals (Grade 5), Quadrilaterals (Grade 6)

right

MathsFrom Grade 1

The side opposite to left.

Learn it in: Position and direction (Grade 1)

right angle

MathsFrom Grade 3

A square corner (90°).

Full explanation with examples and practice →

Learn it in: Right angles (Grade 3), Introduction to other angles (Grade 3), Perpendicular lines (Grade 4)

right triangle

MathsFrom Grade 4

Has a 90° angle.

Learn it in: Classifying triangles (Grade 4), Triangles (Grade 5)

rise

MathsFrom Grade 5

Increase.

Learn it in: Line graphs (Grade 5)

roll

MathsFrom Grade 1

Turn over and over.

Learn it in: Spheres (Grade 1)

rotational symmetry

MathsFrom Grade 5

Looks the same after a turn.

Learn it in: Symmetry (Grade 5)

round

MathsFrom Grade 1

Shaped like a ball or a ring.

Full explanation with examples and practice →

Learn it in: Circles (Grade 1), Checking answers (Grade 2), Rounding to the nearest ten (Grade 3)

round down

MathsFrom Grade 3

Stay on the lower ten.

Full explanation with examples and practice →

Learn it in: Rounding to the nearest ten (Grade 3), Rounding to the nearest hundred (Grade 3)

round up

MathsFrom Grade 3

Go to the next ten.

Full explanation with examples and practice →

Learn it in: Rounding to the nearest ten (Grade 3), Rounding to the nearest hundred (Grade 3)

rounding place

MathsFrom Grade 4

The digit we round to.

Learn it in: Rounding (Grade 4), Rounding (Grade 5), Rounding decimals (Grade 5)

row

MathsFrom Grade 1

Things side by side, left to right.

Learn it in: Numbers to 100 (Grade 1), Picture graphs (Grade 1), Arrays (Grade 2)

rule

MathsFrom Grade 1

What happens each time.

Learn it in: Number patterns (Grade 1), Creating patterns (Grade 1), Classifying objects (Grade 1)

ruler

MathsFrom Grade 1

A tool marked with centimetres for measuring length.

Learn it in: Introduction to centimetres (Grade 1), Measuring length (Grade 2), Line segments (Grade 4)