Mathematics Number Representation & Place Value Conceptual 13–14 yrs

Number Sets & Infinity

数集与无穷

Description

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

Mastery Evidence

✓ 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

Assessment Prompt

Can your child explain that numbers like √2 and π can't be written as exact fractions — and that their decimal expansions go on forever without repeating?