The conditions under which explicit instruction in checking, combined with worked examples, may be beneficial in learning how to translate sentences into algebraic equations was examined from the perspective of cognitive load theory. In two experiments it was shown that Grade 8 and 9 students were initially disadvantaged by the inclusion of a checking method. However, after a more substantial period of acquisition, students with a low level of mathematical knowledge performed significantly better after receiving checking instructions than those who did not receive checking instructions. In contrast, higher knowledge students were continually disadvantaged by the inclusion of a checking method. The positive effect of checking for lower knowledge students and the negative effect for higher knowledge students in this domain is a further example of the expertise reversal effect.