This study examined the development of indirect addition as an alternative for solving multidigit subtractions, by means of two learning environments in traditionally schooled third-graders in Flanders (Belgium). Thirty-five third-graders, who did not demonstrate mastery of indirect addition, participated in an Explicit (n = 20) or Implicit (n = 15) learning environment that aimed to encourage the development of indirect addition. Over a period of six weeks, children participated in nine individual sessions: four practice sessions, three test sessions, one transfer session, and one retention session. The results revealed that throughout the study indirect addition was rarely used, even by the children in the explicit learning environment. However, when indirect addition was used, it was executed very efficiently. (Contains 5 tables.)