The Puffin series is aimed at children aged 4 and above.  There are three books in the series.   The first book introduces the concepts of numbers very gradually.  The understanding of quantities and values are further explored through the introduction of higher numbers with a particular emphasis on place values in the second book.   Following from this thorough basic understanding of number concepts, the third book focuses on numbers up to 100 where you child will gain knowledge of how tens and units fit together.  By the end of the thrid book, your child will be able to add up numbers to 99 using the Japanese abacus (soroban).

These books can also be used for children with maths learning difficulties.  They take children back to the most basic concepts of numbers and build up their knowledge and confidence as they go through the books.