Overview
This lecture explains how to use the make-ten strategy to simplify mental addition by adjusting numbers to create easy-to-add combinations.
Make-Ten Strategy
- The make-ten strategy involves adjusting numbers so one addend becomes a ten, making addition easier.
- When one number is close to ten, use part of the other number to "make" a ten.
- Example: 9 + 5 becomes 10 + 4, so the sum is 14.
- This works by visualizing numbers as quantities, not just symbols.
- For larger numbers, round one addend up and decrease the other by the same amount.
- Example: 29 + 16 becomes 30 + 15, which equals 45.
- For much larger numbers: 298 + 57 becomes 300 + 55, which equals 355.
Visual Models
- Use a double ten frame to visually demonstrate making tens before moving to pictorial representations.
- Visual models help students see the logic behind adjusting numbers.
Key Terms & Definitions
- Make-ten strategy — a mental math technique where numbers are adjusted to form a ten, simplifying addition.
- Ten frame — a visual aid with boxes used to help understand number combinations up to ten.
Action Items / Next Steps
- Practice the make-ten strategy with various pairs of numbers.
- Use double ten frames to model the strategy visually before doing calculations mentally.