This paper studies mathematics learning gaps within Indian children at two points in time. Dividing them into two groups, better performing and the rest, we investigate the causes of the difference in the average learning gap between them at those two points. We explore this question using the threefold Blinder-Oaxaca decomposition at these survey points (collected over a gap of four years). We find that when the children were younger the private schooling effect was the core contributor towards this learning gap. When these children got older, the effect vanished and the gap in average years of schooling, which has magnified during this time between these groups of children, contributes most to this learning gap.