Strategies for Adding 7, 8, and 9
🦸♀️ 7, 8, and 9 are big numbers! But we have a secret superhero strategy to deal with them: making a 10!
Concept
When you need to add big single digits like 7, 8, or 9, counting on your fingers takes too long. Let's use our "Make 10" superpowers! 🎯 **The "Make 10" Strategy:** **Example:** Let's solve **8 + 5 = ?** 1. **Find the 10-maker:** 8 is super close to 10. It only needs 2 more. (8 + 2 = 10) 2. **Borrow from the other number:** Take that 2 away from the 5. (Now the 5 becomes a 3). 3. **Make 10!** Give the 2 to the 8. Now you have 10 + 3. 4. **Add to 10:** 10 + 3 is easy! It's 13. So, **8 + 5 = 13**. This works perfectly for 9, too! 9 is just 1 away from 10. **Example:** **9 + 6 = ?** Take 1 from the 6 (it becomes 5). Give it to the 9 (it becomes 10). Now you have 10 + 5. The answer is 15!
Try it
Let's practice the "Make 10" superhero strategy! **Instructions:** Borrow from the smaller number to make a 10, then add the rest. **Problem 1: 9 + 4 = ?** * Take 1 from the 4. Now the 4 is 3. * 9 becomes 10. * What is 10 + 3? ___ * Answer: 9 + 4 = ___ **Problem 2: 8 + 6 = ?** * 8 needs 2 to make 10. * Take 2 from the 6. What is left? ___ * 10 + ___ = ___ * Answer: 8 + 6 = ___ **Problem 3: 7 + 5 = ?** * 7 needs 3 to make 10. * Answer: ___ **Problem 4: 9 + 8 = ?** * (Hint: Make 10 out of the 9!) * Answer: ___