四舍五入估算
Estimating by rounding
利用四舍五入进行近似，估算答案并计算可能产生的误差，用不等式 a < x ≤ b 表示；理解四舍五入后数值的上限和下限。
Use approximation through rounding to estimate answers and calculate possible resulting errors expressed using inequality notation a < x ≤ b; understand upper and lower bounds of rounded values
学习证据 / Evidence
- 用合理的四舍五入估算计算答案
- 计算四舍五入后测量值的上限和下限
- 用不等式符号表示误差区间
- Estimate the answer to a calculation by rounding all values appropriately
- Calculate upper and lower bounds of a rounded measurement
- Express error intervals using inequality notation
评估问题 / Assessment
如果一段长度按四舍五入到厘米测量为 7 厘米，{{name}} 能否说出实际长度可能在 6.5 厘米到 7.5 厘米之间——理解四舍五入会产生一个可能的取值范围？
If a length is measured as 7 cm to the nearest cm, can {{name}} say the actual length could be anywhere from 6.5 cm to 7.5 cm — understanding that rounding creates a range of possible values?