Breaking down their genes mathematically Lol
He used one to trick his father, and when the panel viewed out there was Bolt, and a clone next to him. Meaning two.
Naruto used the Kyuubi's chakra to make one-hundred clones, and that was the Multi-shadow clone Jutsu. Boruto probably used the shadow clone jutsu itself. And yes, it is impressive, considering the level of the technique, and what it does to the reserves with each clone created. Even Madara praised Naruto after using it. Plus, Edo-Tobirama could create about 2-3 and he was about 1/4 of his real power because of the Edo-Tensei limit. If Boruto can create that many clones at his age, imagine his reserves at prime, but that's not even worth talking about because this is a mini series.
Also -- Boruto was confirmed to be a Prodigy on the Boruto-movie website. So, your "mathematics" on genes, is pretty accurate alright.