Here are a few options for the description of the WordPress post tag “乘法原理” (Chéngfǎ Yuánlǐ – The Multiplication Principle) in Traditional Chinese, depending on the desired context and level of detail:

**Option 1: Simple & Concise (Good for a broader audience)**

> 數學中一種基本的計數原理，用來計算多個步驟結合所產生的總可能性。了解如何運用乘法原理解決排列組合問題。
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> * *A basic counting principle in mathematics, used to calculate the total possibilities resulting from the combination of multiple steps. Learn how to apply the multiplication principle to solve permutation and combination problems.*

**Option 2: More Descriptive (Suitable for students or those looking for a bit more detail)**

> 乘法原理，又稱積法則，是排列組合中的基石。它指出，如果完成一件事需要多個步驟，且每個步驟的選擇都是獨立的，那麼完成這件事的總方法數就是每個步驟方法數的相乘。 本標籤下的文章將深入探討乘法原理的應用，包含各種例題和練習，幫助您掌握計數的核心概念。
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> * *The Multiplication Principle, also known as the product rule, is a cornerstone of permutations and combinations. It states that if a task can be completed in multiple steps, and the choices for each step are independent, then the total number of ways to complete the task is the product of the number of ways for each step. Articles under this tag will delve into the applications of the Multiplication Principle, including various examples and exercises, to help you master the core concepts of counting.*

**Option 3: Emphasis on Practical Application (For a problem-solving focused site)**

> 在解決排列組合問題時，乘法原理是您不可或缺的工具。本標籤文章將提供實用的技巧和步驟，教你如何正確地應用乘法原理，快速有效地計算各種可能性。從簡單的選擇到複雜的排列，這裡都有您需要的知識。
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> * *The Multiplication Principle is an indispensable tool when solving permutation and combination problems. This tag’s articles will provide practical techniques and steps, teaching you how to correctly apply the Multiplication Principle and quickly and efficiently calculate various possibilities. From simple selections to complex arrangements, you’ll find the knowledge you need here.*

**Option 4: Short & Sweet (Best for space constraints)**

> 學習乘法原理 – 輕鬆理解多步驟計數的技巧與應用。
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> *Learn the Multiplication Principle – Easy to understand the techniques and applications of multi-step counting.*

**Key Considerations when choosing:**

* **Audience:** Who are you writing for? (Students, general audience, etc.)
* **Purpose:** What do you want people to gain from the tag? (Understanding, problem-solving skills, etc.)
* **Word Count:** WordPress tag descriptions can be short, but more detail is often better.

Choose the option that best suits your WordPress site and your intended audience! I’ve provided translations for clarity. You can also choose to omit them, as the tag itself will mostly be for Chinese-speaking users.