People do not have innate mechanisms for complex calculations (e.g. math). However, children typically do spontaneously come up with some form of counting without being explicitly taught. It may be that counting knowledge is innate but it is also possible that this develops through imitation and that children, while being able to count, do not know the meaning of these numbers. At three and a half years of age, children know that the order in which one recites numerals is crucial. Young children are able to point out subtle counting errors (e.g. count something twice) and by four years of age, children have mastered the basics of how to count. Children do not know the meaning of counting until the end of their fourth year. Children tend to come up with calculation algorithms without explicit instruction (e.g. adding numbers up using their fingers). Children initially have big difficulties in counting without their fingers and may explicitly state their process (i.e. name what they are doing), though this requires a lot of effort and concentration. The minimum strategy refers to starting an addition equation with the larger quantity and count a number of times equal to the smaller of the two numbers (e.g. 4 + 2 = four, five, six, six!). This strategy underlies most of children’s calculations before the onset of formal schooling. Children develop an intuitive understanding of commutativity (i.e. a+b=b+a) without any formal schooling. Between the ages of 4 and 7, children exhibit an intuitive understanding of what calculations mean and how they should best be selected.Young adults rarely solve addition and multiplication problems by counting but retrieve results from a memorized table. Accessing this table takes longer as the operands get larger. This may be due to the accuracy of mental representations dropping with number size (1), order of acquisition influencing memory (2) and the amount of drilling (i.e. less training with larger number...