Addition and subtraction within 10 - Find the difference - Presentation

In Lesson 21, students are encouraged to expand their understanding of subtraction by learning how to find the difference between two numbers. This fundamental mathematical concept is approached through a series of engaging activities where students apply their counting skills, both forwards and backwards within 20, to practical scenarios. The lesson begins with a discussion prompt to get students thinking about addition and subtraction in the context of finding differences. Through visual aids and questions such as "How many more cakes does Tia have than Malachi?" the lesson aims to make subtraction relatable and easy to grasp.

The lesson is structured around interactive activities that invite students to compare quantities and calculate differences. For example, students are presented with images of Tia and Malachi, each with a different number of cakes, and are asked to determine how many more cakes Tia has. This exercise is repeated with various items and numbers, reinforcing the concept of finding the difference through subtraction. Additionally, the lesson includes reasoning tasks where students must consider the difference between two numbers given certain conditions, like when the larger number is less than 10. To further support understanding, students are encouraged to use tangible resources such as cubes, counters, or images to visually represent and solve problems, thereby solidifying their ability to find the difference in a variety of contexts.