理解角度（8岁及以上）
Understanding angles (age 8+)
通过边长相乘求长方形的面积，并将整数乘积表示为长方形的面积。
Multiply side lengths to find areas of rectangles and represent whole-number products as rectangular areas
学习证据 / Evidence
- 计算一个7厘米×9厘米的长方形的面积，得到63平方厘米。
- 画一个面积为36平方单位的长方形，并标出它的边长。
- 解答：一个花园长8米、宽5米，它的面积是多少？
- Calculate the area of a 7 cm × 9 cm rectangle as 63 cm²
- Draw a rectangle with area 36 square units and label its side lengths
- Solve: A garden is 8 m by 5 m — what is its area?
评估问题 / Assessment
如果{{name}}需要给一个长5米、宽4米的房间铺地毯，能不用数方格，而用乘法算出需要买多少地毯吗？
If {{name}} needs to carpet a room that is 5 m by 4 m, can they work out how much carpet to buy — using multiplication rather than counting squares?