1st Class @ Number is an intervention programme that we use for children that need more support with mathematics. It is a ten week programme that is delivered by teaching assistants. The children attend the intervention in addition to their daily mathematics lessons. The lessons focus on number and calculation, developing children’s mathematical understanding, communication and reasoning skills. A Post Office theme runs throughout, engaging children in real life contexts that are both stimulating and fun. Each topic starts with a simple assessment that helps the teaching assistant to tailor sessions to the children’s needs.