FIGURE 8.13 Young children’s strategy choices in (a) addition, (b) subtraction, and (c) multiplication As illustrated previously with reading (Figure 8.10), a strong positive correlation exists between the difficulty of a problem, as defined by the percentage of errors it elicits, and the frequency of using an overt strategy, such as counting on one’s fingers. Thus, for problems that 4- and 5-year-olds found easy, such as 2 + 2, they usually used retrieval. For problems they found difficult, such as 4 + 3, they usually used overt strategies, such as counting from 1. (Siegler, 1986)