Looking at CCSS 8.NS today, I posed the question: What kinds of numbers do we know already? Student responses included prime, composite, odd, even, positive, negative, fractions, and decimals. We looked at number sets and how/where do their responses fit. This definition for rational numbers (found in a grade level text) matched their description of fractions including a numerator and denominator.
I was curious, though, what they’d do with decimals–that they might see rational numbers ONLY as fractions after reading this. Not a problem!! 🙂 Happy teacher!!