How do you explain...?

[Kevin]

I'm convinced that the reason why fractions were so intuitive to me compared to most of my classmates when the subject came up in math classes was the fact that I had a much bigger musical background from playing the piano, singing in choirs since I was 6, and later band. Whole notes, half notes, quarter notes, eighth notes, sixteenth notes, triplets, 4/4 time, 3/4 time, 2/4 time, cut (1/2) time, 6/8 time, 6/4 time, 2/3 time... music uses fractions all over the place. Plus, you get not just an intellectual feel but also a visceral feel of the fractions from the music.

Yep.

Some of the studies that have tried to show why music helps kids learn better has tested stuff like this as well. The correlation between musical and traditional education is fairly strong and well known, the causation not as much but this is one of those factors.

If the kids have any sort of a good teacher, kids that play baseball tend to be pretty good at fractions as well as unit conversion because of batting averages and ERA. For most people grounding a concept to something they are familiar with in a different setting is very effective for teaching.