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'.