P1 · Number · NUM.COUNT.20
Count to 20
Count to 20
Intuition
Understand first, compress later.
Connect symbolic calculation to magnitude, estimation and a visual representation.
Switch representations
Number line0 … 10
Formal view
You can count to 20 when you can recognise the underlying objects, select valid rules and check each step for equivalence or logical implication.
Why does it work?
This skill sits on a prerequisite network. If a step is unstable, repair the missing prerequisite instead of merely doing more items of the same type.