Clever Near Doubles
🕵️♀️ Use your doubles knowledge like a detective! If you know a double fact, you can solve the problems right next to it. We call these "near doubles" or "neighbors of doubles".
Do this: Read the concept below, then try the quiz or activity.
Concept
This is a super smart trick to solve addition problems that are close to a double you already know.
The "Doubles Plus One" Strategy Let's solve 6 + 7. 1. Find the smaller number: It's 6. 2. Think of its double: You know that 6 + 6 = 12. 3. Realize the relationship: The problem 6 + 7 is just ONE MORE than 6 + 6. 4. Solve: So, the answer must be one more than 12. It's 13! * 6 + 7 = 13
The "Doubles Minus One" Strategy Let's solve 8 + 7. 1. Find the bigger number: It's 8. 2. Think of its double: You know that 8 + 8 = 16. 3. Realize the relationship: The problem 8 + 7 is just ONE LESS than 8 + 8. 4. Solve: So, the answer must be one less than 16. It's 15! * 8 + 7 = 15
Both strategies give you the right answer! You can choose whichever one makes more sense to you.
Try it
Let's be a near-doubles detective!
Instructions: Use the double fact to help you solve the near-double problem.
Problem 1: You know 5 + 5 = 10. So, what is 5 + 6? ___
Problem 2: You know 7 + 7 = 14. So, what is 7 + 8? ___
Problem 3: You know 8 + 8 = 16. So, what is 8 + 7? ___
Problem 4: You know 6 + 6 = 12. So, what is 6 + 5? ___
Problem 5: Solve 9 + 8 using a near-doubles strategy. Show your thinking!
🏆 Three Numbers Challenge: How can you use doubles to solve 4 + 4 + 1? * First solve the double: 4 + 4 = ___ * Then add the 1: ___ + 1 = ___