L9 Add and Subtract Capacity

Develop pupils' confidence in measurement calculations with this engaging Year 3 lesson on adding and subtracting capacity. Aligned with the National Curriculum, this resource helps children apply their understanding of litres (l) and millilitres (ml) to solve a range of practical problems involving volume and capacity. Through carefully structured activities, pupils learn how to add and subtract capacities accurately, including calculations that require converting between litres and millilitres. Children revisit key measurement concepts before progressing to word problems that encourage them to interpret information, select appropriate operations and explain their reasoning. The lesson provides opportunities to compare capacities, make unit conversions and solve both one-step and multi-step problems involving real-life contexts. Pupils are encouraged to think critically about whether a situation requires addition or subtraction and to represent their thinking using number sentences and efficient calculation strategies. Designed to address common misconceptions, the resource helps children understand the relationship between litres and millilitres, recognise when conversions are necessary and avoid comparing measurements based solely on the numerical value. Practical problem-solving activities build fluency while strengthening mathematical reasoning and confidence. Ideal for whole-class teaching, intervention sessions, independent practice or mastery learning, this lesson supports children in developing a secure understanding of capacity calculations and applying measurement skills in meaningful contexts.