"Algebrization"
Patterns → Formulas.

  • "Find the Pattern" ; then "Find a Formula"

    There are two angles to "pattern"!
    (Or: "pattern" isn't the same as "formula"!)

    Less experienced students think mostly/only about the "vertical" pattern:

    Pattern 1: Pattern 2:
    21
    43
    65
    87
    ..
    ..
    ..

    In both cases the "Vertical Pattern" is:

    'add one at each step'

    But the two "patterns" (sequences) have different formulas!