**Problem:** $30 - 9 = ?$ **Start with 30 stars:** ⭐ ⭐ ⭐ ⭐ ⭐ ⭐ ⭐ ⭐ ⭐ ⭐ ⭐ ⭐ ⭐ ⭐ ⭐ ⭐ ⭐ ⭐ ⭐ ⭐ ⭐ ⭐ ⭐ ⭐ ⭐ ⭐ ⭐ ➖ **Take away 9 stars:** ~~⭐ ⭐ ⭐~~ ~~⭐ ⭐ ⭐~~ ~~⭐~~ **What's left:** ✨ **You have 21 stars left!** **Math:** $$30 - 9 = 21$$