Mental maths is still a key part of the end of KS2 National Tests and so schools are striving for pupils to do even better than the average Level 3. This book follows on from Mental Maths in Minutes 9-11 so is ideal for stretching very able pupils but is also an excellent resource for the first year of secondary school. Specific skills such as addition, subtraction, doubling, halving, multiplying and dividing are addressed repeatedly, but each time at a higher level of understanding. As with the other books in the series, the Extension book features forty mental maths practice sheets together with forty matching answer sheets. Each sheet has at least two, and normally four, columns of questions that pupils can answer quickly. Guidance for teachers suggests that the sheets are used at the start of maths lessons and that pupils should be given one minute for each column. Andrew has found a particularly successful technique is for pupils to complete one column, mark it themselves and then do a second column straight away to see if they can improve on their mark. An entire sheet takes approx 10 minutes which makes it perfect for lesson starters.