Fourth grader solving 16-7=? with body system

You have 16 pigs; you give seven away; how many left? The 4th grader begins his solution of the problem with the ear-on-the-other-side (16). He indicates that this (ear (16) is given away, and corresponds to the thumb (1); the eye on the other side (15) is given away, and that corresponds to the index finger (2); the nose (14) is given away, and that's the middle finger (3)... the child proceeds to the shoulder (10) is given away and that's the forearm (7), leaving biceps (9), the answer. In theĀ Cultural Development of Mathematical Ideas, this approach is refered to as a "double enumeration" strategy. Children are not taught the approach; it's an approach that emerged as Oksapmin children made efforts to make sense of the mathematics taught in school in the post-colonial approach to schooling. (1980)