To answer the question "The term 'Mathematical tools' refers to," we will analyze the options provided and determine which one best encompasses the concept of mathematical tools.
### Step-by-Step Solution:
1. **Identify the Options**: The options given are:
- A) Calculators, rulers, tape measures, protractors, compass, etc.
- B) Charts based on formulas, concepts, graph papers, dotted sheets, etc.
- C) All types of materials including language, written symbols, meaningful instructions to establish their purpose.
- D) Physical materials like Jobode and 3D models, cubic rods.
2. **Analyze Each Option**:
- **Option A**: This option lists specific tools commonly used in mathematics, such as calculators and rulers. These are indeed mathematical tools, but they represent only a subset of what mathematical tools can be.
- **Option B**: This option includes charts and graph papers, which are also important in mathematical practice. However, it focuses on specific types of materials rather than the broader concept of mathematical tools.
- **Option C**: This option is broader and includes all types of materials, including language, written symbols, and meaningful instructions. This captures the essence of mathematical tools as it encompasses both physical tools and conceptual aids.
- **Option D**: This option mentions physical materials but is quite limited in scope compared to option C.
3. **Determine the Best Answer**:
- While options A, B, and D include valid examples of mathematical tools, they do not cover the full range of what mathematical tools can be. Option C, however, includes all types of materials and concepts that can aid in mathematical understanding and problem-solving.
4. **Conclusion**: Therefore, the best answer is **Option C**: All types of materials including language, written symbols, meaningful instructions to establish their purpose.
