加法与减法策略（10岁以上）
Addition and subtraction strategies (age 10+)
能够基于位值、运算性质以及加减法之间的关系，运用策略计算两位小数（精确到百分位）的加法和减法；能将策略与竖式写法相联系，并解释推理过程。
Add and subtract decimals to hundredths using strategies based on place value, properties of operations, and the relationship between addition and subtraction; relate strategies to written methods and explain reasoning
学习证据 / Evidence
- 正确计算 3.45 + 2.78，并解释小数数位之间的进位与退位。
- 用数轴或十进制积木演示 5.03 − 2.67 的计算过程。
- 通过联系位值理解，解释为什么标准竖式算法适用于小数加法。
- Correctly compute 3.45 + 2.78 and explain regrouping across decimal places
- Use a number line or base-ten blocks to model 5.03 − 2.67
- Explain why the standard algorithm works for decimal addition by connecting to place-value understanding
评估问题 / Assessment
{{name}}能否正确计算像“4.73 + 2.68”或“10.00 − 3.47”这样的小数加减题，并在计算时对齐小数点、按位逐列计算？
Can {{name}} add or subtract decimal amounts like '4.73 + 2.68' or '10.00 − 3.47', lining up the decimal points and working through the columns correctly?