Addition and subtraction - Add three-digit and ​two-digit numbers crossing 100 - Starter

This Year 3 mathematics lesson from the Autumn Term's fifth week, day four, is designed to enhance students' fluency in addition and subtraction through practical exercises. The lesson begins with a revision activity using a place value chart to solidify understanding of number sentences. Students are tasked to divide numbers like 80 by 10, reinforcing their comprehension of how division affects place value. They are also required to perform simple calculations such as dividing 65 by 5, which encourages mental arithmetic skills.

Further exercises involve adding and subtracting multiples of ten to a three-digit number, specifically 159, to deepen their grasp of place value and the effects of these operations on the hundreds, tens, and ones columns. For example, students calculate the results of 159 plus 2 tens, minus 5 tens, and plus 4 tens, with the answers being 179, 109, and 199 respectively. Additionally, the lesson includes completing bar models to visually represent the calculations, which helps students to understand the concept of value in a different format. The activity also incorporates a practical element where students write descriptions of a route taken, which includes directions and movements, thus integrating mathematical understanding with everyday contexts.