In Mathematics this week our main focus will be on composition, as we complete work on the NCETM's week 8 of the Mastering Number Programme.
Composition of number is a key area of mathematics, and children need considerable and varied practice over time, based on meaningful experiences, to build their understanding of this concept.
This week, the children will begin to explore composition by focusing on the preliminary skills: the concept of ‘wholes’ and ‘parts’. By investigating their own bodies and familiar toys they will begin to understand that whole things are often made up of smaller parts and that a whole is, therefore, bigger than its parts.
Key language in this area can be tricky; clarity around a ‘whole’ and how it is different from a ‘hole’ needs to be made explicit. You can use gesture to support this. Further confusion can arise from other composition language, e.g. when do we mean ‘a part’ and how is this different from ‘apart’? Use this week’s stem sentences to help consolidate understanding.
Understanding the composition of numbers is more than remembering number facts. As part of their work on subitising, the children have previously begun to spot numbers within numbers, and this skill of de-composing and combining numbers (taking them apart and putting them back together again) will build firm foundations for later calculation strategies. When children can compose and flexibly de-compose numbers mentally, they will become more fluent in their knowledge of number bonds and they can use these to become efficient when calculating in KS1 and KS2.
As the children move through Reception, they will explore the composition of numbers alongside their developing skills of conceptual subitising. Learning that parts can be combined in different ways to make a whole will support the children’s understanding of commutativity (i.e. adding 2 and 1 together gives the same result as adding 1 and 2) and associativity in KS2, where parts are combined to support efficient calculating, such as seeing 7 + 2 + 8 as 7 + 10 rather as than 9 + 8.