Mental thinking: Using the target number strategy is a set of prepared classroom activities which give students the opportunity to use mental thinking strategies for addition; subtraction; multiplication; money; fractions; decimals; measurement; and making combinations using the four operations, brackets and indices. Mental thinking develops flexibility and gives students the necessary skills to solve problem situations in their head or by manipulating numbers based on standard and non-standard partitioning. The use of the 'make the target number strategy' is designed as a mental thinking activity. The activities are developmental and, therefore, teachers can set work at different levels to suit the needs of individual or groups of students. The activities in the book are open-ended problems, which allows for students from any level to respond to the target number according to their understanding of mathematics. The activities focus on 'look for all possibilities' and 'guess, check and improve' problem-solving strategies.