Addition and subtraction - 10 more and 10 less - Presentation

Lesson 8 of the addition and subtraction series focuses on the concept of finding 10 more and 10 less than a given two-digit number. The lesson encourages students to explore what is meant by 'more' and 'less' through a series of engaging activities. One of the key activities involves continuing number tracks to identify patterns and understand the relationship between numbers when 10 is added or subtracted. For example, students are presented with sequences like 10, 20, 30 and 35, 45, 55, and asked to continue these patterns to reinforce their understanding of the concept.

The lesson further develops this understanding by using a hundred square, where students circle the number that is 10 more or 10 less than numbers like 27 and 34, using different colours to highlight the changes. This visual aid helps students to notice patterns and the consistency of the difference between numbers when 10 is added or subtracted. Additionally, students use concrete materials to fill in empty boxes, reinforcing the concept through hands-on learning. For example, they are asked to determine what number is 10 more or 10 less than numbers like 2, 37, and 24. Through these activities, students develop a solid grasp of basic arithmetic operations and the ability to reason with numbers in a practical context.