Popular descriptions of how children secure the answers to addition operations, according to Effie Maclellan, may be contributing to confused thinking. Distinctions appear to be made between adding ‘on paper’, ‘with a calculator’ and ‘with concrete materials’. The author maintains that such distinctions are real only in the sense that they distinguish between the trappings of addition. This may well be deflecting us from the more essential issue, which is the nature of the mental strategies children use