Recommended number of stems Whiteboard exercise Play

Rectangles Student activity Play

Reduction formulas for the cosine Animation Play

Reduction formulas for the sine Animation Play

Reflection symmetry in the coordinate system in the x-axis and the y-axis Student activity Play

Relationship between the group number and the number of valence electrons Animation Play

Relative atomic mass Whiteboard presentation Play

Relative atomic mass Class activity Play

Relatively prime numbers Whiteboard exercise Play

Reversing the percentage change Student activity Play

Rolling 6 Animation Play

Rolling a die Animation Play

Rolling a die Whiteboard exercise Play

Rolling a number greater than or equal to 7 Whiteboard exercise Play

Rolling an odd number Whiteboard exercise Play

Roots of roots – finding true equations Whiteboard exercise Play

Roots of roots – more examples of true or false equations Whiteboard exercise Play

Rounding a number Animation Play

Rounding decimals Whiteboard exercise Play

Rounding decimals Whiteboard exercise Play

Rounding decimals Student activity Play

Rounding decimals to 0.01 Student activity Play

Rounding decimals to 0.1 Student activity Play

Rounding decimals to 0.1 or to 0.01 Animation Play

Rounding decimals to 10–1 or to 10–2 Student activity Play