This book starts by revising numbers to 99 and then it goes on to the transition from 99 to 100 on the Addacus, showing that 10 tens are 1 hundred. By providing a secure grounding in place value and base 10 the book then easily introduces money and the writing of money which leads on naturally to decimal fractions and the recording/writing of decimal fractions. Fractions of numbers are introduced in a concrete way using number strips and stringalongs. Time is taught innovatively using a clock line which is easily divided into 12 five strips thus relating it back to the 5 x table. Pupils then curl the line round to make a clock and add the hands and arrow cards to represent the time in analogue, digital or the 24 hour clock. Clock cards provide the opportunity to play games and learn to tell the time. The 6,7,8,9 times tables are taught as in book 2 using songs, cards and “speed wheels” Calculations practising the processes of number +, -, x and division to 999 lead to the ability to record these operations in columns (HTU).