Here are a few options for the description of a WordPress post tag with the title “八加七” (Eight plus Seven) in Traditional Chinese, catering to different needs and levels of detail:

**Option 1: Concise & Clear (Best for general use)**

> 數學概念：八加七 (Eight plus Seven)。 涵蓋加法運算及相關內容。 (Mathematical concept: Eight plus Seven. This covers addition and related content.)

**Option 2: Slightly More Descriptive**

> 關於算數的帖文，標記為「八加七」。 專注於討論數字「八」與「七」相加的數學概念，以及與此相關的題目和解說。 (Posts about arithmetic, tagged with “Eight plus Seven.” Focusing on the mathematical concept of adding “eight” and “seven,” as well as related problems and explanations.)

**Option 3: Focus on Education/Learning**

> 學習加法，「八加七」等於多少？ 這個標籤用於包含關於加法運算的教學資源，例題，以及練習題。 適合學習數學基礎的學生。 (Learning addition, what does “Eight plus Seven” equal? This tag is for teaching resources about addition, examples, and practice problems. Suitable for students learning the basics of mathematics.)

**Option 4: Simple & Broad**

> 包含關於「八加七」的一切。 (Encompassing everything about “Eight plus Seven.”)

**Option 5: (If you have multiple tags for math)**

> 數學： 八加七的計算結果。 進一步探索加法概念，以及如何解决涉及「八加七」的數學問題。 (Mathematics: The result of Eight plus Seven. Further exploring the concept of addition and how to solve math problems involving “Eight plus Seven.”)

**Key considerations when choosing:**

* **Your Audience:** Who are you writing for? (Students, general readers, etc.)
* **Content Focus:** What *specifically* will be tagged with this? (Just the answer? An explanation? Problems?)
* **Tag Usage:** How do you intend to organize your content with tags?
* **Clarity:** Keep the description clear and easy to understand.
* **Consistent Tone:** Use a similar tone and style as your other tag descriptions.

I recommend choosing the option that best matches the overall purpose of your blog or website and the specific content associated with this tag. Option 1 or 2 are generally good starting points. Good luck!