分数加法概念

理解分数的加法和减法就是合并和分开部分；会利用同分母分数相加，用不止一种方式分解一个分数。

Understand addition and subtraction of fractions as joining and separating parts; decompose a fraction into a sum of fractions with the same denominator in more than one way

学习证据 / Evidence

• 展示3/8 = 1/8 + 1/8 + 1/8，也展示3/8 = 1/8 + 2/8。
• 写出5/6的两种不同分解方式。
• 使用直观模型说明2 1/8可以分解成整数部分和分数部分。

• Show that 3/8 = 1/8 + 1/8 + 1/8 and also 3/8 = 1/8 + 2/8
• Write two different decompositions of 5/6
• Use a visual model to justify a decomposition of 2 1/8 into whole-number and fraction parts

评估问题 / Assessment

如果{{name}}有7/8块巧克力，送出了3/8，能算出还剩多少吗？还能用两种不同的方法把7/8拆成两部分吗？

If {{name}} has 7/8 of a chocolate bar and gives away 3/8, can they work out what fraction is left — and then show two different ways to split 7/8 into two parts?