Addition and subtraction - Add two-digit and one-digit numbers - Presentation

In the educational presentation titled "Add Two-digit and One-digit Numbers," students are introduced to the concept of adding a two-digit number to a one-digit number, with a specific focus on partitioning to aid in calculations that cross the tens boundary. The term 'partitioning' is discussed, which is a technique used to break down numbers into parts to simplify the addition process. The lesson encourages students to consider whether they can hold the larger number in their head and count on the smaller number, using examples such as starting at 17 and counting on 5, or starting at 16 and counting on 6.

The presentation guides students through various activities that involve visual and numerical strategies to enhance their understanding of addition. For instance, one activity demonstrates how to use number bonds to partition numbers like 5 into 3 and 2, which helps to 'bridge the 10'—a method that makes it easier to add numbers that result in a sum crossing into the next ten. Using base 10 blocks, students are encouraged to draw and partition numbers to visually represent the addition process, highlighting the exchange of 10 ones for 1 ten when necessary. The lesson also includes reasoning exercises where students are prompted to think about the outcomes of adding ones to a two-digit number and the effect on the tens digit. Overall, the presentation aims to solidify students' fluency in addition while developing their reasoning skills through interactive and thought-provoking activities.