Number Book is a series of graded activity books designed to help children learn basic calculation skills including addition, subtraction, multiplication and division. Number Book 2 is suitable for children making the transition from the Early Years Foundation Stage to Key Stage 1 and includes: using a number line to count on and back the addition of three numbers, mixed addition and subtraction sums number facts (for example pairs of numbers that add up to 10), comparing numbers to find which is 'more' or 'less'.