### ***Practice 1 - Concrete-Representational-Abstract (CRA)*** ![[Pasted image 20260421141832.png]] CRA is a three-stage instructional framework that begins with physical manipulatives such as base-ten blocks or counters, moves to drawn representations such as tally marks or bar models, and finally arrives at abstract number sentences. In subtraction, this means students physically remove objects before they are ever expected to compute symbolically. |Pros|Cons| |---|---| |Builds genuine conceptual understanding before procedural fluency.|Requires significant planning and preparation of materials at each stage.| |Strong research support especially for students with learning disabilities.|Transitioning between stages requires careful teacher monitoring.| |Applicable across all subtraction types including regrouping.|Some students resist manipulatives past early elementary if not introduced early.| **** ### ***Practice 2 - Count Up Strategy*** ![[Pasted image 20260421141850.png]] The count up strategy teaches students to subtract by counting forward from the smaller number to the larger number rather than counting backward from the minuend. For example, to solve 13 — 8, a student counts up from 8 to 13 and tracks 5 jumps. This leverages students' stronger addition skills to support subtraction. |Pros|Cons| |---|---| |Uses addition knowledge students already have, reducing new cognitive load.|Can be slower than standard algorithms for larger numbers.| |Highly effective for students who struggle with the concept of "taking away."|Requires students to track jumps accurately which can be difficult without a number line.| |Easy to scaffold with fingers, tally marks, or a number line.|Does not transfer directly to multi-digit subtraction with regrouping without additional instruction.|