Addition and subtraction within 20 - Add ones using number bonds - Presentation

In a mathematics lesson centred around addition and subtraction within 20, students are introduced to the concept of using number bonds to add single-digit numbers to larger ones. The lesson begins with a simple question that encourages students to consider the number of ones in a given number, such as 14. The focus is on understanding and utilising number bonds to facilitate addition. For example, when adding 12 and 4, students break down the number 12 into 1 ten and 2 ones, and then add the 4 ones to arrive at the total of 16, which is composed of 1 ten and 6 ones. This method emphasises the decomposition of numbers into tens and ones to simplify the addition process.

Further activities in the lesson guide students through similar addition problems, such as adding 11 and 7 or 15 and 3, using the same approach to break down numbers into their constituent parts. Students also engage with part-whole models as a visual aid to understand how numbers combine to form a total. The lesson includes independent work where students apply their knowledge of adding ones and number bonds to complete calculations and identify any mistakes in given examples. The goal is to reinforce their understanding of addition within 20 and to develop fluency in using number bonds as a strategy for efficient calculation.