Personalized Sailing 100 Days 3rd Grade Youth T-Shirt. Funny 100th Day of School Youth T-Shirt - White for 3rd grade, primary school teachers with sailboat and stars. My Kids Sailed Through 100 Days of 3rd Grade. Celebrate your students being 100 days smarter. Let the good times roll in a durable T-Shirt that takes kids from school to play in an amazing array of colors. 5.0 oz., pre-shrunk 100% cotton. Seamless 1x1 rib collar.