**Example of Tactile Design:**

** Open- and Solid-Circle Number Line**

The following points indicate the braille code, format rules, and design techniques that were used for this tactile graphic example.

- Nemeth braille code
- extension of axis line segments to allow space for multi-digit values (2.9)
- use of Special Symbols page to explain braille dot symbols (5.13, 6.5.1.13)
- non-use of numeric indicators for labels below the number line (6.5.1.1)
- use of blank lines before and after number line and labels (Nemeth rules for spatial arrangement) (6.5.1.2)
- inclusion of arrowheads as in print (6.5.1.3)
- no alteration of open and solid circles because they are mathematically significant (6.5.1.6)
- alignment of first digit of numeric label with regular scale mark (6.5.1.8)
- placement of ordinary labels (6.5.1.8)
- arrangement of number line on same line as itemized answer choices A-D. (6.5.1.9)
- use of embossed braille symbols allowed for grades 4 and up (6.5.1.13)
- placement of regular scale marks embedded within number line (6.5.1.13)
- placement of open and solid circles above number line (6.5.1.13)

**Open- and Solid-Circle Number Line**

**Open- and Solid-Circle Number Line**