Just hold a pellet an inch or so from the water and see if your betta will jump for it... some do, some don't. Only one of my bettas is willing to jump for pellets, but my oscar is more than happy to jump the full length of his body to snag one
One of my Plakats will jump two inches straight vertically for a pellet (or even just a nibble of my finger), and then slip again straight vertically back into the water. It's quite funny. I didn't even train him to do it. I just took his lid off one day, and he jumped up and bit me.
One of my female would jump even without food (approx. 3 inches) and the other female would only jump if there was pellet-on-a-stick. My male betta on the other hand cannot jump for some reason. Using pellets and toothpick to get your betta to jump is a good idea but make sure you smooth the ends.