The central idea of teaching with variation is to highlight the essential features of a concept or idea through varying the non-essential features
Variation is not the same as variety – careful attention needs to be paid to what aspects are being varied (and what is not being varied) and for what purpose.
NCETM The 5 Big Ideas of Teaching for Mastery
Procedural variation provides the opportunity
for practice (intelligent rather than mechanical);
to focus on relationships, not just the procedure;
to make connections between problems.
When constructing a set of activities or questions it is important to consider what connects the examples; what mathematical structures are being highlighted?
Students are encouraged to avoid mechanical practice and, instead, to practice the thinking process (intelligent practice)
Research suggests that mathematical thinking occurs when students are thinking about mathematical structure.
Multiple representations allow students to gain a deeper understanding of the mathematical structure.
Comparing multiple methods allows students make connections and use the most appropriate method with fluency.
Comparing different representations uncovers the structure of the mathematics and allows students to make generalisations.
Carefully planned variation reveals mathematical structure.