加减法策略

使用接着数和倒着数的策略来完成加减法。

Use counting on and counting back as strategies for addition and subtraction

学习证据 / Evidence

• 通过从8开始接着数3个数来计算8 + 3（9、10、11）。
• 通过从12开始倒着数3个数来计算12 − 3（11、10、9）。
• 能解释接着数是做加法的一种方法。

• Add 8 + 3 by starting at 8 and counting on 3 (9, 10, 11)
• Subtract 12 − 3 by counting back 3 from 12 (11, 10, 9)
• Explain that counting on is a way to add

评估问题 / Assessment

如果{{name}}要计算“8 + 5”，他们能不能不从1开始数，而是从8开始再往后数5个数？

If {{name}} needs to work out '8 + 5', can they start from 8 and count up five more — rather than starting from 1 every time?