Should I just ask him or try to find out?

I like this guy from school, and he may like me back, but i don't know what do. I've only been at my new school for 4 weeks and really like him. I think he likes me because of this... We were the first two to complete our S&E test and we sit near each other. We were writing stuff on our calculators with the numbers and then showing them to each other. Then he wrote i love you with it. But he didn't look like he was joking or just typing it coz he could. He had a look on his face that was shy and he was blushing at me. I've only known him for 4 weeks though and I don't know if I should ask him out or test him to see if he wants to go out with me. Plz help!!