数集与无穷
Number Sets & Infinity
体会整数集、实数集和有理数集的无限性；能在数轴上表示整数，并区分有理数与无理数。
Appreciate the infinite nature of the sets of integers, real numbers, and rational numbers; position integers on a number line and distinguish between rational and irrational numbers
学习证据 / Evidence
- 解释有理数可以写成两个整数的比，其小数形式要么有限，要么循环。
- 举出无理数的例子，并说明它们的小数展开既不会终止也不会循环。
- 体会在任意两个数之间都存在无穷多个其他数。
- Explain that rational numbers can be written as a fraction of two integers and have terminating or repeating decimals
- Give examples of irrational numbers and explain why their decimal expansions neither terminate nor repeat
- Appreciate that between any two numbers there are infinitely many other numbers
评估问题 / Assessment
{{name}}能解释像√2和π这样的数不能写成精确的分数，而且它们的小数展开会无限继续、不循环吗？
Can {{name}} explain that numbers like √2 and π can't be written as exact fractions — and that their decimal expansions go on forever without repeating?