Play Hop Star to practice addition, subtraction, multiplication, division. Mental math facts for 1st graders, 2nd graders, 3rd graders, 4th graders & 5th graders boys & girls. Solving math & coding problems has never been so much fun for first, second, third, fourth grade kids. With Skidos Hop Star, your kids will learn fast math skills in an easy step-by-step way.