Addition and subtraction within 20 - Subtraction not crossing 10 - Starter

In the Year 1 mathematics lesson focusing on subtraction within 20, specifically on cases that do not require crossing the number 10, students begin with a 'Fluent in Four' revision exercise. This starter activity is designed to help children practice their addition and subtraction skills through a series of questions. For example, they are asked to double the number 0 and then add half of 18, which results in 9. Another question prompts them to add eight to 8, yielding 16. The exercise includes a practical component where the children use counters to assist with their calculations, reinforcing their understanding of basic arithmetic concepts through tactile learning.

The lesson also incorporates an exploration of number bonds to 8, encouraging students to identify different pairs of numbers that add up to 8. Examples provided include 1 + 7, 2 + 6, and 3 + 5, among others, illustrating the concept of number bonds through various combinations. Additionally, students are presented with a problem-solving question where they must determine who has half of 14 between two characters, Esin and Zach, with Esin being the correct answer. To further develop their numerical skills, the children are tasked with arranging a set of numbers from different groups in ascending order, from least to greatest, thereby practicing number sequencing and comparison. This multifaceted approach to learning subtraction within 20 allows for a comprehensive understanding of the subject matter.