Addition and Subtraction - Adding 2 three digit numbers (exchange) - Presentation

The educational material focuses on enhancing the arithmetic skills of pupils by teaching them how to add two three-digit numbers, especially when such addition leads to crossing the tens or hundreds boundary. The lesson begins with a discussion about the maximum value that can exist in a place value column, setting the stage for understanding exchanges in addition. Through a series of activities, students explore the concept of exchanging when the sum in the ones or tens column reaches ten or more. For example, in one activity, students are presented with the problem of adding 266 and 336, and they are asked to consider what happens when there are 10 ones. The visual aids provided in the form of place value charts and pictorial representations help students to see the process of carrying over or exchanging in a tangible way.

Subsequent activities delve deeper into the concept, such as adding 276 and 346, and observing what occurs when there are both 10 ones and 10 tens. Students use column addition to solve various problems and compare pictorial representations to understand the consistency of the addition process. Real-life applications, such as calculating the total points scored in a game or the total miles driven by two cars, further reinforce the practicality of the skill. The lesson also includes reasoning exercises where students roll dice to create three-digit numbers and explore different outcomes, such as achieving odd or even totals or multiples of five. The material encourages critical thinking by asking students to justify their answers and understand the importance of correct digit placement in addition.