等值分数（9岁以上）
Equivalent fractions (age 9+)
借助直观模型解释为什么一个分数 a/b 等于 (n×a)/(n×b)；并运用这个原理识别和生成等值分数，包括十分之几和百分之几。
Explain why a fraction a/b is equivalent to (n×a)/(n×b) using visual models; use this principle to recognise and generate equivalent fractions, including tenths and hundredths
学习证据 / Evidence
- 用分数条展示 2/3 = 4/6 = 6/9。
- 说明分子和分母同时乘同一个数得到的是等值分数，因为整体的大小没有改变。
- 写出三个与 3/5 相等的分数，并用图验证。
- Use a fraction strip to show 2/3 = 4/6 = 6/9
- Explain that multiplying numerator and denominator by the same number gives an equivalent fraction because the size of the whole is unchanged
- Generate three fractions equivalent to 3/5 and verify with diagrams
评估问题 / Assessment
如果{{name}}需要把 2/3 换一种写法但不改变它的大小，能不能把分子和分母同时乘同一个数，并解释为什么分数不变？
If {{name}} needs to make 2/3 look different without changing its value, can they multiply the top and bottom by the same number and explain why the fraction stays the same?