Addition and subtraction within 20 - Add ones using number bonds 2 - Presentation

In the continuation of a mathematics lesson focused on addition and subtraction within 20, the concept of adding ones using number bonds is presented to students. The lesson aims to deepen understanding of how number bonds can facilitate addition calculations. For example, if students are familiar with the fact that 4 plus 3 equals 7, they are encouraged to explore how this knowledge helps them deduce that 14 plus 3 equals 17. The lesson begins by discussing related calculations and prompting students to think about the relationship between simple number bonds and more complex ones.

Through a series of activities, students are guided to apply their knowledge of number bonds in practical examples. They start with basic additions such as 2 plus 5, recognising that this equals 7 ones. The lesson then extends this understanding to larger numbers, breaking down numbers like 12 into 1 ten and 2 ones, and then adding 5 to reach a total of 17. Students are encouraged to complete part-whole models themselves, reinforcing the concept that understanding number bonds to 10 provides a foundation for knowing number bonds to 20. They are then challenged with a range of addition problems to solve independently, ensuring they apply their number bond knowledge to verify the accuracy of their calculations.