If he likes a combination of math and business strategy, he should look into a career in data analytics. This could be achieved through a variety of college majors since the field is still somewhat nascent, but rapidly growing. Pretty much any fortune 100 company now requires candidates business strategy candidates with the ability to run models using big data tools such as Hive, Hadoop, Spark, R, etc. This is because companies these days have access to trillions more datapoints than they did a decade ago and determining the mathematical significance behind that data is driving the decisions of today’s most successful companies. This isn’t limited to tech companies anymore so he could work in any industry with this skillset. In terms of college major, any combination of comp sci, business, and math could pursue this career track, but if not including at least a minor in comp sci, he would have to learn some of the languages on his own, which is what I did.