C1
Basic Multiplication Principle
乘法原理
Counting / 计数Grades G3 - G5
👀
What It Looks Like
Recognition signals — when you see these, think of this structure:
- 1Multiple independent choices or stages
- 2Words like 'and' connecting separate decisions
- 3Questions about combinations of different types of items
🎯
What It Really Tests
The core mathematical idea behind this structure:
If there are m ways to do one thing and n ways to do another, there are m × n ways to do both.
如果做一件事有m种方法，做另一件事有n种方法，则两件事一起做有m×n种方法。
⚠️
Why Students Get Stuck
Common mistakes to watch out for:
- ⚠Adding instead of multiplying
- ⚠Not recognizing choices as independent
- ⚠Double-counting overlapping options
💡
Your First Step
How to begin thinking about problems with this structure:
Count choices at each step independently, then multiply.
分别计算每一步的选择数，然后相乘。
Related Structures
These structures share similar patterns or thinking approaches: