We examined the relation between self-explaining and encoding among kindergartners. For 5 days, children (n = 27) took turns solving addition problems with an adult expert who always used an advanced addition strategy. During the game, children explained the expert's answers (Explain-Expert), explained their own answers (Explain-Novice), or did not generate explanations (Control). Encoding of the expert's strategy was measured each day by asking children to describe how the expert had solved the last problem. Explain-Expert children encoded more and learned more than children in the Control group; Explain-Novice children showed neither advantage. The Explain-Expert group also acquired the expert's strategy more rapidly and used it more frequently than the other groups. These results suggest that explanations enhance learning in part by facilitating encoding.