The three steps of CRA are interdependent, and a conceptual structure can be established by using CRA, thus forming the meaning connection of knowledge.
The first stage of the CRA strategy, namely the example (c) stage, is a "do" stage. At this stage, teachers use processed materials for modeling (Resource Center, 2004). These materials include colored disks, cubes, decimal building blocks, six-color building blocks, fractional building blocks and so on. When using these materials, children's visual, tactile and dynamic experiences must be taken into account.
The second stage, that is, the description (R) stage, is a "look" stage. At this stage, the specific model has been changed to picture display (Resource Center, 2004), and teachers can use hand-drawn pictures or stickers to explain concepts.
The last stage, the abstract (a) stage, is the abstract "symbol" stage (Resource Center, 2004). At this stage, teachers use mathematical symbols such as numbers and letters (such as 2, 6, 3x,+,-,etc. ) to teach.
The premise of using CRA is that students must learn concepts before learning "rules". Students who have used processed materials will have clearer thinking and understand this way more easily, and their learning motivation, focused behavior and ability to understand and use these concepts will be greatly improved (HRRISON &; Harrison, 1986).
CRA strategy can effectively help students understand the following concepts: early quantitative relationship, bit value, calculation, fraction, decimal, measurement, geometry, currency, percentage, number base, application problem and probability statistics (Table 2.3 of Resource Center 20040 describes the progressive process from example (with a disk) to description (with a number axis) to abstraction (with numbers).
-from "Teaching and Behavior Intervention (RTI)" Carla Shore.